Trade-Space Analysis of a Small Unmanned Vehicle System for Radiological Search Missions

Nuclear and radiological terrorism is a persistent threat to United States national security. The research and development of new technological capabilities is vital to bolstering emergency response and prevention capabilities in support of national security initiatives. This research characterized the applicable trade-space for a system of unmanned vehicles deployed for search, detection, and identification of radiological source material. Exploration included the development of a CONOPS, a functional decomposition and physical allocation, design considerations, and an analysis of feasibility and utility. The concept system comprises of a ground control station, ground vehicle, hybrid-electric multirotor, and fixed-wing vehicle with an open architecture permitting the exchange of payload components. Payload options include a Geiger-Müller detector or scintillator for large area search and a scintillator or high purity germanium semiconductor for radioisotope identification. Endurance estimates revealed that a hybrid-electric multirotor is capable of carrying a 6.8-kilogram payload for 58 minutes. Similar estimates indicated that a battery-powered fixed-wing vehicle can provide a minimum of 41 minutes of endurance with a payload mass fraction of 15% (1.36-kilogram payload), whereas a gasoline-powered vehicle with the same payload mass fraction (1.95-kilogram payload) can operate for 12 hours. Electric multirotors are limited to a maximum endurance of 20 minutes, which is insufficient for radiological search missions. The system concept proves effective to the radiological search mission and can be expanded to other mission areas through its open architecture

Model-Based Evaluation of Energy Systems for Multirotor UAV Based on Batteries and Fuel Cells

In this study, two multirotor unmanned aerial vehicle (UAV) energy systems are comparatively evaluated via a modelling process, namely a battery electric system and a hybrid fuel cell and battery system. Technical, economic, and ecological evaluation parameters are considered. The evaluation is performed on three different mission types: a 10 km delivery mission, a 3000 m2 facade inspection, and a nine-minute drone show, to represent the transport, monitoring, and event sectors. Results are calculated via a modelling process first simulating the required power profiles for each mission and then simulating both energy systems’ operational behavior during each mission. The resulting technical parameters show that the battery electric UAV has 1.7 times higher efficiency than the fuel cell hybrid UAV. However, the fuel cell hybrid UAV allows potential flight durations 3.1 times longer than the battery electric UAV. Considering economic parameters, the battery electric UAV is the more economical choice due to the higher investment costs of the fuel cell hybrid UAV, even when considering future cost developments for investment and energy costs. For ecological parameters, the fuel cell hybrid UAV has the potential to produce significantly less emissions, but only when using hydrogen produced from renewable energy (green hydrogen). All in all, the battery electric UAV is sufficient for the three concrete missions considered and should be chosen over the fuel cell hybrid UAV. However, the fuel cell hybrid UAV should be considered for missions with longer required flight times than the battery electric UAV is capable of, especially in the transport and monitoring sectors

Design Considerations for Autonomous Cargo Transportation Multirotor UAVs

Unmanned aerial vehicles (UAVs) have proven to be an advanced tool for a variety of applications in the civilian and military sectors. Different categories of UAVs are used in various missions and are also the subject of numerous researches. Due to their characteristics and potential in specific conditions, multirotor UAVs imposes itself as a solution for many tasks, including transport. This chapter presents a conceptual solution of autonomous cargo transportation where the primary research objective is the design of a heavy lift multirotor UAV system. The process of designing a multirotor UAV that can carry heavy lift cargo is quite challenging due to many parameters and constraints. Five selected series of electric propulsion systems are analyzed, with different multirotor configurations, and results are graphically displayed for payloads from 10 kg up to 100 kg

Internet of Things 36-rotor Multicopter for Ionizing Radiation Surveying

This paper presents an Internet of things 36-rotor unmanned aerial vehicle suitable for radiological surveying of buildings and facilities. The design of the 36-rotor multicopter platform is disclosed. The aircraft is used as a testbed for a lightweight gamma/beta/neutron ionizing radiation sensor closely coupled with the autopilot of the multirotor aircraft. A prototype of the drone and sensor was developed and initial tests were conducted. Test results are presented with data from measuring different radiation sources. The proposed novel design is compared to existing work and advantages to the latter were established

Recent Efforts Enabling Martian Rotorcraft Missions

The Mars Helicopter (MH), launching as a part of the Mars 2020 mission, will begin a new era of planetary exploration. Mars research has historically been conducted through landers, rovers, and satellites. As both government and private industries prepare for human exploration of the Martian surface within two decades, more in depth knowledge of what awaits on the surface is critical. Planetary aerial vehicles increase the range of terrain that can be examined, compared to traditional landers and rovers and have more near surface capability than orbiters. The Jet Propulsion Laboratory (JPL) and NASA Ames are currently exploring possibilities for a Mars Science Helicopter (MSH), a second-generation Mars rotorcraft with the capability of conducting science investigations independently of a lander or rover (although this type of vehicle could also be used assist rovers or landers in future missions). Preliminary designs of coaxial-helicopter and hexacopter configurations have targeted the minimum capability of lifting a payload in the range of two to three kilograms with an overall vehicle mass of approximately twenty kilograms. These MSH designs sizes are constrained by the aeroshell dimensions(currently focused on employing legacy Pathfinder or MSL aeroshells), rather than vehicle structural or aeroperformance limitations. Feasibility of the MSH configurations has been investigated considering packaging/deployment, rotor aerodynamics, and structural analysis studies. Initial findings suggest not only the overall feasibility of MSH configurations but also indicate that improvements up to 11.1 times increase in range or 1.3 times increase in hover time might be achievable, even with an additional science payload, compared to the current design of the MH

Autonomous UAS-Based Agriculture Applications: General Overview and Relevant European Case Studies

Emerging precision agriculture techniques rely on the frequent collection of high-quality data which can be acquired efficiently by unmanned aerial systems (UAS). The main obstacle for wider adoption of this technology is related to UAS operational costs. The path forward requires a high degree of autonomy and integration of the UAS and other cyber physical systems on the farm into a common Farm Management System (FMS) to facilitate the use of big data and artificial intelligence (AI) techniques for decision support. Such a solution has been implemented in the EU project AFarCloud (Aggregated Farming in the Cloud). The regulation of UAS operations is another important factor that impacts the adoption rate of agricultural UAS. An analysis of the new European UAS regulations relevant for autonomous operation is included. Autonomous UAS operation through the AFarCloud FMS solution has been demonstrated at several test farms in multiple European countries. Novel applications have been developed, such as the retrieval of data from remote field sensors using UAS and in situ measurements using dedicated UAS payloads designed for physical contact with the environment. The main findings include that (1) autonomous UAS operation in the agricultural sector is feasible once the regulations allow this; (2) the UAS should be integrated with the FMS and include autonomous data processing and charging functionality to offer a practical solution; and (3) several applications beyond just asset monitoring are relevant for the UAS and will help to justify the cost of this equipment.publishedVersio

An Omnidirectional Aerial Platform for Multi-Robot Manipulation

The objectives of this work were the modeling, control and prototyping of a new fully-actuated aerial platform. Commonly, the multirotor aerial platforms are under-actuated vehicles, since the total propellers thrust can not be directed in every direction without inferring a vehicle body rotation. The most common fully-actuated aerial platforms have tilted or tilting rotors that amplify the aerodynamic perturbations between the propellers, reducing the efficiency and the provided thrust. In order to overcome this limitation a novel platform, the ODQuad (OmniDirectional Quadrotor), has been proposed, which is composed by three main parts, the platform, the mobile and rotor frames, that are linked by means of two rotational joints, namely the roll and pitch joints. The ODQuad is able to orient the total thrust by moving only the propellers frame by means of the roll and pitch joints. Kinematic and dynamic models of the proposed multirotor have been derived using the Euler- Lagrange approach and a model-based controller has been designed. The latter is based on two control loops: an outer loop for vehicle position control and an inner one for vehicle orientation and roll-pitch joint control. The effectiveness of the controller has been tested by means of numerical simulations in the MATLAB c SimMechanics environment. In particular, tests in free motion and in object transportation tasks have been carried out. In the transportation task simulation, a momentum based observer is used to estimate the wrenches exchanged between the vehicle and the transported object. The ODQuad concept has been tested also in cooperative manipulation tasks. To this aim, a simulation model was considered, in which multiple ODQuads perform the manipulation of a bulky object with unknown inertial parameters which are identified in the first phase of the simulation. In order to reduce the mechanical stresses due to the manipulation and enhance the system robustness to the environment interactions, two admittance filters have been implemented: an external filter on the object motion and an internal one local for each multirotor. Finally, the prototyping process has been illustrated step by step. In particular, three CAD models have been designed. The ODQuad.01 has been used in the simulations and in a preliminary static analysis that investigated the torque values for a rough sizing of the roll-pitch joint actuators. Since in the ODQuad.01 the components specifications and the related manufacturing techniques have not been taken into account, a successive model, the ODQuad.02, has been designed. The ODQuad.02 design can be developed with aluminum or carbon fiber profiles and 3D printed parts, but each component must be custom manufactured. Finally, in order to shorten the prototype development time, the ODQuad.03 has been created, which includes some components of the off-the-shelf quadrotor Holybro X500 into a novel custom-built mechanical frame

Design of a quadcopter to work at high temperatures

The project develops the design of a quadcopter to work within industrial plants which can be found even at 80 degrees Celsius. These plants should be checked as a way of detecting faults or cracks to prevent other serious incidents that may arise. Both the whole building as well as industrial machinery, which are inside the plant, should be inspected without the need to wait until the infrastructure is fully cooled down. Both external mechanical defense to get close to surfaces, adapting to customer specifications, as well as mechanical and electronic components in the multicopter are designed. It shall support all the requested temperature at least 80 degrees.El proyecto desarrolla el diseño de un cuadricóptero para trabajar dentro de plantas industriales que se pueden encontrar hasta una temperatura de 80 grados. Estos edificios deben ser revisados continuamente como una forma de detectar fallas o grietas que puedan evitar otros incidentes más graves que pudieran surgir. Todo el edificio, así como la maquinaria industrial que están dentro de la planta, deben ser inspeccionados sin la necesidad de esperar hasta que la infraestructura está totalmente enfriada ...Ingeniería Industria

Universal UAV Payload Interface

Unmanned Aerial Vehicle (UAV) technology is becoming increasingly accessible for civilian use. Both open-source and commercial-purpose UAVs can be obtained affordably or even built. However, the platforms available are very segmented in their customization to a specific application (i.e. land surveying, payload delivery). This project aims to create a Universal Payload Interface (UPI) mounted to the underside of multi-rotors or other UAVs to enable the attachment of customizable sensor payloads. These payloads allow a single UAV to be rapidly reconfigured to perform a multitude of tasks. The Universal Payload Interface facilitates communication between the payload, onboard flight controller, and operator ground station as well as providing power to the payload from the UAV DC bus. Both autonomous and manual flight regimes are supported. By using the open-source MAVlink protocol, the UPI is not restricted to one particular flight controller or ground station platform