Hybrid Airship Research Articles

Designing a PID Pitch Controller with HIL Solution for Maintaining Stability and Controllability of a Hybrid Airship

Designing a PID Pitch Controller with HIL Solution for Maintaining Stability and Controllability of a Hybrid Airship

Variational Method-Based Trajectory Optimization for Hybrid Airships

Hybrid airships, combining aerodynamic lift and buoyant lift, are efficient near-space aircraft for scientific exploration, observation, and surveillance. Compared to conventional airplanes and airships, hybrid airships offer unique advantages, including stationary hovering and rapid deployment. Due to the different task requirements and strong coupling between flight and environment, trajectory-optimization methods for traditional aircraft are difficult to apply to hybrid airships directly. We propose a trajectory-optimization model based on the variational method to calculate the optimal time and energy paths under weak, uniform, and latitudinal linear wind fields. Our model shows that the influencing factors for the optimization path can be categorized into three types: airship design parameters, wind field parameters, and departure parameters. The result indicates that the optimal time paths are generally straight lines, and the optimal energy paths are piecewise curves with a 24-h cycle under typical hybrid airship design parameters. This work has provided new insight into the trajectory optimization and parameter design of future hybrid airships.

A parametric design approach for multi-lobed hybrid airships

AbstractIn recent years, there has been an increasing interest in the research and development of hybrid airships for various applications. Airship design involves multiple design parameters from various disciplines that interact mutually. Existing design methodologies, however, are often limited to fixed shapes and geometry. This paper provides a comprehensive parametric design approach for the sizing of multi-lobed hybrid air vehicles for low- and high-altitude applications. The proposed design techniques are robust so that the designer has the freedom to change the number of lobes, the relative location of lobes, the envelope profile, and the optimiser for the design optimisation process. The outcomes of the proposed methodology are envelope volume, wetted surface area, length and span of the envelope, sizing and layout of the solar array, and sizing and layout of the fins. The modeling techniques highlighted in this paper are very efficient for the design and optimisation of multi-lobed airships in the conceptual design phase with a large design exploration space. The robustness of the shape generation algorithms is tested on some of the standard envelope profiles of airships. The effect of the shape and geometry of the multi-lobed envelope on added mass is demonstrated through the added mass estimation using Boundary Element Method.

Об организационных структурах управления продовольственной и пожарной безопасностью в Центральной Сибири

The article is devoted to the problems of self-organization of science-intensive technological processes in agriculture and fire protection of farmland and forests. Examples of modern solutions in the field of monitoring farmland and forests using unmanned aerial vehicles, small aircraft and helicopters are given. The latest achievements in the development of airships for these purposes are described, including a method patented by the authors for detecting and fighting fires using gas separation nanotechnology to replace the main fire extinguishing agent (water) with atmospheric nitrogen. The conditions for self-organization of technological processes in agriculture are determined. The results of the synthesis of the model of a "fire-agricultural combine-airship", combining "inside itself" not only the functions of fire extinguishing with separated atmospheric nitrogen, but also all agricultural technologies and precision farming equipment - "without tractors, seeders, harvesters, trucks and reclamation systems" are given. Keywords: AGRICULTURAL TECHNOLOGIES, UNMANNED AERIAL VEHICLES, AGRICULTURAL AVIATION, ANTI-FIRE AVIATION, MEMBRANE AIR SEPARATORS, INTEGRATION OF SAFETY AND AGRICULTURAL TECHNOLOGIES, HYBRID AIRSHIPS

Развитие интеграции технологических процессов точного земледелия и противопожарной защиты

Due to the existing problems of food security in the world, the work aimed at solving them is highly relevant. As a result of the analysis of various approaches in agriculture and fire protection, the need for integration of technological processes was identified. As part of this, a system synthesis of an agro-fire harvester-airship model was performed, which combines all agrotechnologies and precision farming techniques with the functions of extinguishing fires with atmospheric nitrogen separated by a membrane nitrogen station. The simulation results confirming the possibility of extinguishing fires with supersonic streams of cooled nitrogen from a height of 50 m are presented. They confirm that agro-fire combines-airships have an uncomprehensible advantage not only in extinguishing fires of farmland and woodlands, but also in the organization of agriculture, due to the proposed integration of innovative solutions. Keywords: AGRICULTURAL TECHNOLOGIES, UNMANNED AERIAL VEHICLES, AGRICULTURAL AVIATION, FIRE-FIGHTING AVIATION, MEMBRANE AIR SEPARATORS, INTEGRATION OF SAFETY TECHNOLOGIES AND AGRICULTURAL TECHNOLOGIES, HYBRID AIRSHIPS

Longitudinal Trim and Stability Analysis of Hybrid Airship with Suspended Payload for Single Body and Two Body Dynamics Using Bifurcation Method

Longitudinal Trim and Stability Analysis of Hybrid Airship with Suspended Payload for Single Body and Two Body Dynamics Using Bifurcation Method

Hybrid Airship Fuel Optimization for Various Cruise Modes

Hybrid airships are new-age air transportation vehicles that consume lesser fuel than conventional airplanes and take lesser flight time than conventional airships. In the present study, hybrid airship fuel consumption during cruise is minimized by optimizing volume and lift apportionment through optimization. In literature, cruise mode 1 (varying cruise speed), cruise mode 2 (varying lift coefficient), and combination of cruise modes 1 and 2 are detailed. This paper introduces two novel cruise modes, namely, cruise mode 4 (varying atmospheric density cruise) and cruise mode 5 (constant dynamics pressure cruise). All five cruise modes are investigated and formulated by posing as optimization problems considering fuel weight minimization as the objective function. Fuel weight minimization has been carried out for two time constraints (24 and 36 h). The optimization problems were solved using MATLAB optimization toolbox. From the results, it is found that cruise modes 4 and 5, which are having the highest mean total ratio and highest mean buoyancy ratio, provide least fuel consumption. The results indicated that cruise modes 1, 2, and 3 require 5–7% more fuel than cruise modes 4 and 5.

Design and analysis of hybrid electric multi-lobed airship for cargo transportation

Though a lot of curiosity has been developed towards a sustainable mode of cargo transportation, multi-lobed hybrid airships are touted to be a viable alternative to the conventional aircraft. The advantages of these Lighter Than Air (LTA) vehicles can further be boosted by incorporating a renewable source of energy. The requirements of high power in cargo airships and the current technological barriers call for the development of a hybrid propulsion system that can couple the best of both conventional and electric propulsion. The electric propulsion system is established by integrating solar arrays with fuel cells, which is then combined with conventional engines in a parallel power train architecture ensuring minimum transfer of energy and compact size. A solar irradiance model is adopted, to evaluate the amount of energy generated by the solar arrays installed over the airship envelope. A multi-lobed hybrid airship model is presented whose aerodynamic characteristics are obtained using computational fluid dynamic tools, which are then utilized to evaluate the power requirements through flight performance analysis. The hybrid propulsion system is then modified in accord with the power needs of the hybrid airship. Finally, detailed weight distribution between hybrid-powered and conventional hybrid-airship is presented displaying significant reduction in fuel weight of ∼350 kg due to the hybrid propulsion system.

Conceptual Design and Feasibility Study of Winged Hybrid Airship

In recent years, hybrid airships have been identified as promising alternatives for high altitude, long endurance missions. In this study, a design methodology to study the feasibility of a winged hybrid airship powered by solar energy is presented. The proposed methodology involves five disciplines of the airship, viz., geometry, aerodynamics, environment, energy and structures that have been coupled in order to develop an optimum design which incorporates the maximum advantages of the modules. A total of fourteen design variables have been finalized, which are required to carry out the sizing of the envelope, wing, and solar panel layout. The Particle Swarm Optimization (PSO) algorithm is implemented to carry out optimization of a user-defined fitness function for given user-defined operating conditions. The optimization study is subjected to general constraints of weight balance and energy balance. Optimal solutions have been obtained for two different configurations. These are—conventional airship and winged hybrid airship. The solutions have been obtained for four different days of the year, in order to analyse any potential benefits and pitfalls of the two configurations for the varying conditions over the course of one year. The results obtained are generally found to be in excellent agreement with the imposed constraints. The winged hybrid airship configuration was found to have offered no significant benefits in comparison to the conventional configuration. The analysis of the key parameters and data values readily supports this conclusion.

Global health radiology planning using Geographic Information Systems to identify populations with decreased access to care.

BackgroundCommunities throughout northern Canada face significant health care disparities including decreased access to radiology. A medical hybrid airship is under development which aims to serve remote populations, requiring strategic outreach planning. This study aims to use geographic information systems (GIS) to identify (1) high risk and medically underserved patient populations in northern Canada and (2) potential landing sites for a medical airship to allow for mobile delivery of radiology services.MethodsThe northern region of Canada extending from the Rocky Mountains to the Atlantic Ocean was analyzed using multi-variable, multi-weighted GIS modeling. Based on population distance from hospitals (50% weight), health centers (eg, clinic; 30% weight), remote communities (not connected to electric grid; 10% weight), and roads (10% weight), individuals were stratified into one of five health care accessibility index (HAI) categories (ranging from very low to very high severity). HAI (80% weight) was combined with population density (20%) to create a health care access severity index (HASI). Topographic and land cover data were used to identify suitable landing sites for the medical airship. A coordinate data set was made from georeferenced health care facilities, and infrastructure data was obtained from OpenStreetMap.ResultsGIS analyzed 815 772 Canadians. Of this population, 522 094 (64%) were found to live ≥60 km from a hospital, 326 309 (40%) were ≥45 km from the nearest health center, 65 262 (8%) were within 30 km of a remote community, and 57 104 (7%) lived ≥1 km from the nearest road. Combined, the HASI identified 44% of the population as having decreased access to care (high or very high severity). Lastly, 27.5% of land analyzed was found to be suitable for airship operations.ConclusionsGIS identified medically underserved populations in northern Canada who may benefit from mobile radiology services. These techniques may help to guide future global health outreach efforts.

Study of the features of the characteristics of a hybrid airship turn

the dynamics of aircraft motion is determined, as is well known, by the acting forces. When an airplane is flying, these forces include the total aerodynamic force, the thrust force of the propulsion system, and the force of gravity. Hybrid Airship differs from an aircraft by the presence, in addition to the above, of aerostatic force, the value of which depends, among other things, on the height of flight of the Hybrid Airship. The presence of aerostatic force affects the maneuverability of a Hybrid Airship. The proposed article analyzes the changes in the characteristics of a Hybrid Airship turn caused by the presence of aerostatic force.

Multidisciplinary design approach for solar-powered tri-lobed HALESA

In the recent years, there has been a lot of interest in developing hybrid airships as aerial platforms for various applications because of their several advantageous features. This paper presents a multi-disciplinary design optimization based methodology for an airship with a tri-lobed envelope. The proposed methodology involves five disciplines, viz., Geometry, Environment, Energy, Aerodynamics and Structures. To reduce computational complexity involved in evaluating the aerodynamic characteristics of the tri-lobed envelope, a Kriging-based surrogate model was developed to estimate the envelope drag coefficient and coupled to the optimization framework to achieve the optimal solutions for different operating conditions. The surrogate model predicts the drag coefficient of the tri-lobed envelope with less than ±3% error with respect to the results obtained through CFD. Since the problem follows a multi-disciplinary design approach, a composite objective function is formulated based on volume of the envelope, area of the solar array, and total mass of the airship, which isminimized using Particle Swarm Optimization (PSO) Algorithm. This study reveals that for meeting the same mission requirements, a tri-lobed airship powered by regenerative fuel cells requires half the volume and 33.5% lower solar array area, and has ~46% lower mass compared to the one powered by rechargeable batteries.

Effect of a Circular Slot on Hybrid Airship Aerodynamic Characteristics

This numerical study reports the aerodynamic properties of a hybrid airship. The hybrid airships were designed by combining two semi-ellipsoids with a semi-discoid as the base model. From the base model, three different geometrics were identified to study their aerodynamic characteristics. A circular slot was provided between the pressure side and the suction side of the airship. The objective of this study was to realize the flow behavior, aerodynamic characteristics, and stability properties of such slotted hybrid flying vehicles. Interestingly, the results imply that the lift coefficient increases with an increase in the angle of attack for the slotted configurations; this is because the flow separation is delayed due to the slot opening, which in turn is due to the flow of energies from the high-pressure region to the bottom through the slots. The delayed stall angle was 50 degrees, which was 10% more than that of the base model. Aerodynamic characteristics are discussed based on surface pressure, coefficient of lift, and coefficient of drag for various slotted hybrid airships.

Multidisciplinary design optimization of a lift-type hybrid airship

Multidisciplinary design optimization of a lift-type hybrid airship

Strategic Radiology Outreach Planning for Underserved Populations Using Geographic Information Systems.

Geographic information systems (GIS) are widely used in public health research but rarely used in radiology research. GIS can be an impactful tool in radiology global health to locate medically underserved populations and poor transportation infrastructure, characterize medical needs, and design outreach programs. Using the example of aircraft-based outreach in Alaska, we demonstrate the utility of GIS in radiological program planning for global health. Multicriteria GIS evaluations were performed to create a health severity index, using life expectancy and percentage uninsured data, and an accessibility severity index, using distance from roads and health centers or hospitals. These indices were combined with population density to create a final health access severity index (HASI). A map presenting suitable hybrid airship operating areas was produced using land cover data. Alaskan health care facilities were georeferenced to create a coordinate data set. Infrastructure was obtained from OpenStreetMap. Health data were accessed from the 2017 American Community Survey and CDC US Small-area Life Expectancy Estimates Project. GIS analyzed 738,050 Alaskans. The health severity index identified decreased health outcomes (high or very high severity) in 285,446 (39%) Alaskans, and the accessibility severity index determined decreased access to care in 218,201 (30%). Combined, the HASI established 165,108 (22%) Alaskans as underserved with high or very high overall severity. Thirty-nine percent of Alaska land area is suitable for hybrid airship operations, including 27% of HASI high and very high severity areas. GIS identified underserved populations for mobile radiology outreach in Alaska and may be useful for global health outreach planning and resource allocation.

Expanding the reach of global health radiology via the world's first medical hybrid airship: A SWOT analysis.

Expanding the reach of global health radiology via the world's first medical hybrid airship: A SWOT analysis.

Preliminary Design of a Solar-Powered Hybrid Airship

The feasibility of a solar-powered hybrid airship where lift is generated by both buoyancy and aerodynamics is investigated using aerodynamic shape optimization. The design objective is to minimize the product of envelope root chord and span (which corresponds to the size of the hangar required to house the airship), subject to constraints on the lift, the ratio of solar power produced to power consumed, the airship operational empty weight, the trim, and the static margin. Simple mass models are used to estimate the mass of airship components, including the solar array, drive train components, and envelope fabric. The optimizer has the freedom to vary the envelope section shapes, span, twist, angle of attack, and flap angle. A three-point optimization has produced a feasible envelope geometry that satisfies the design requirements at two cruise-speed operating conditions (each with a center-of-gravity location at either extreme of the design range) and one low-speed operating condition. The results indicate that such an aircraft, which could be well suited to operations in remote areas, is feasible with respect to aerodynamic efficiency. Sensitivity studies indicate that faster hybrid airships will become feasible with future improvements in solar panel irradiance.

Electric hybrid airship with unlimited flight time

This paper examines the possibility of using photoelectric energy conversion during creation of electric unmanned aerial vehicles of a hybrid type. These vehicles should operate at altitudes up to 22,000 m and have an unregulated flight time. The problems arising during creation of such devices are their instability and poor controllability. Also they possess a number of disadvantages typical for airships: large size and, as a consequence, high windage and dependence on weather conditions; low maneuverability and, as a consequence, the difficulty of landing. These negative aspects of all circular wings resulted in complete rejection of their development. However, the considered disadvantages show the feasibility of creating hybrid aircraft. Particular attention in this paper is given to disk-shaped vehicles. They have less windage, do not need to turn around when changing the direction of flight. The presence of solar panels in combination with modern control and navigation systems make it possible to create new unmanned aerial vehicles with unlimited flight time. The aircraft dimensions are calculated as a function of the lifted mass and other parameters. Recommendations on possible operation parameters of hybrid airship are given.

Design optimization of a tri-lobed solar powered stratospheric airship

The increased interest over multi-lobed hybrid airships which have been recently identified as an ideal platform for high altitude long endurance applications urges to develop a methodology for conceptual design optimization. The sizing methodology estimates the area of solar array required to meet the constraints of energy balance and the weight/lift equilibrium. The methodology involves the coupling of four disciplines (viz., Environment, Geometry, Aerodynamics, and Energy) and accounts for their mutual interactions. Sizing of the airship is carried out in terms of five design variables corresponding to the geometry and layout of the envelope and the solar array. This methodology is coupled to an intelligence-based heuristic algorithm viz., Particle Swarm Optimization (PSO) to obtain the configuration corresponding to a minimum area of solar array for such an airship, meeting the user-specified operating requirements. The effect of wind speed, airship attitude and altitude, geographical location and day of operation on the optimum area are included in this study. The results show the effect of season and operating conditions of deployment on the optimal envelope shapes obtained for deployment on specific days of the year. This study helps in the preliminary design of solar array on an unconventional stratospheric airship.

Mission-based multidisciplinary optimization of solar-powered hybrid airship

This paper presented a multidisciplinary optimization methodology of a high altitude solar-powered hybrid airship. A multidisciplinary model of the hybrid airship is proposed including the geometry, aerodynamics, structures, propulsions and energy consisting of the photovoltaic array and energy stored system (ESS). To achieve a continuous flight and reduce the total mass and energy cost, a multi-phase strategy including the climb, daytime cruise, glide and nighttime cruise is proposed. The mission-based optimization is achieved through an enhanced collaborative optimization and the result shows a large decrease in the total mass compared with a baseline design.Since the flight altitude has a great influence on the hybrid airship with the multi-phase strategy, a multi-objective optimization achieved by NSGA-II (Non-dominated Sort Genetic Algorithm-II), is carried out to discuss the design tradeoffs in different altitudes. The result also indicates that the multi-objective optimization provides a solution set so that the optimal design of the hybrid airship in different flight altitudes could be obtained.