. 263 Downloads Abstract Near space airships have gained widespread attention owing to the unique characteristics of long endurance at high altitudes; because of this characteristic, such airships have great potential for use in the fields of communication relay, early warning, earth observation etc. Near space airships can substitute near-earth geostationary satellites owing to the advantages of high load and long endurance at altitude exceeding 20 km. Buoyancy against gravity is generated by the airship hull, which is completely filled with helium, while the near space airship is equipped with an electrical propulsion system powered by solar energy. Unlike conventional aircraft, nearspace airships are a new type of vehicles with less design experience; coupled multi-disciplinary problems related to aerodynamics, structure, energy, control, etc. With the aim of finding a solution for optimal near-space airship design, this study proposed a design using a multidisciplinary design optimization method.
Gabriel Alexander Khoury. More information. AIRSHIP TECHNOLOGY. Second Edition. This comprehensive guide to modern airship design.
ZHU Ming corresponding author was born in 1976. He received the degree of Ph.D. In Beihang University.
He is now an associate professor of BUAA ASE. His research interests include near space aircraft design, UAV system design, UAV control and advanced robot technol-ogy.
(Email: [email protected]) YIN Shi was born in 1990. He is now a doctor candidate of BUAA ASE. He received the master and bachelor’s degree in Beihang University. (Email: [email protected]) LIANG Haoquan was born in 1984.
He is now a postdoctoral candidate of BUAA School of Automation Science and Electrical Engineering. He received the doctor, master and bachelor’s degrees in Beihang University. (Email: [email protected]) ZHANG Xiayang was born in 1991. He is now a doctor can-didate of BUAA ASE.
He received the bach-elor’s degree in Bei-hang University. (Email: [email protected]) This work is supported by The National Natural Science Foundation of China (No.51307004).
Abstract: Based on the Kirchhoff equations, Newton-Euler laws, boundary layer theory and mass definition, the six degrees of freedom dynamic model of airship complete with aerodynamic forces, wind effect is presented. Then, the nonlinear dynamic model is divided into three group equations by restricting airship motion in different planes respectively. The motion characteristics of airship, including stability, the effect of ballast position and rotational damping, are studied using linearized model. The results of simulation verify the correctness of the theoretical analysis and airship design.
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Abstract: This paper presents a method for solving the station-keeping problem of near-space airship (NSA) at an altitude of 22km above sea level with wind influence. Firstly, according to the system overall configuration, the nonlinear mathematical model of NSA is established. Secondly, considering the steady wind and turbulence influences, the station-keeping control law of NSA longitudinal plane which divided into forward control loop and vertical control loop is designed. The vertical position control loop adopts the dual PID control method. In order to improve attitude response performance and decrease energy consumption of actuators, attitude control allocation strategy between fins and vectored thruster is provided.
At last, the simulation experiment proves the validity of the proposed station-keeping control method of NSA. Abstract: It has important scientific and engineering applications for near-space platform to design the buoyancy-lifting aircraft with both bigger volume and higher aerodynamic efficiency.
This paper provided a design of a new concept V-shaped airship which has a capacity of buoyancy-lifting configuration than the same-weight class conventional airship. In addition, two engines could provide rolling, yawing and pitching moments for the V-shaped airship by changing directions and creating different thrust. Based on the thick aerofoil, the geometry of this V-shaped configuration was then used to develop an aerodynamic estimating model for the V-shaped airship. It renewed estimating methods for the added mass, inertia, the forces and the moments including aerodynamic and engine thrust of the V-shaped airship. Then this paper described a 6 Degree of Freedom (DOF) dynamic model for the V-shaped airship. The open-loop disturbance characteristic of the dynamic model was analyzed across a range of flight conditions and the added mass of the V-shaped airship were compared with the same weight-class teardrop-shaped dull-hull airship.
Finally, the characteristics of buoyancy and lift between V-shaped airship and dull-hull airship were compared at different velocity. The results show that the aerodynamic efficiency of the V-shaped airship is improved obviously from the same-weight class dull-hull airship across a range of flight velocity. Abstract: This paper presents dynamics modeling approach of the near-space airship.
First, reference frames and motion variables of the airship are defined, and dynamics model of an airship is derived from the Newton-Euler formulation. Second, the Lagrangian modeling approach in terms of quasi-coordinates is presented, and dynamics model is derived form the Lagrangian formulation, considering the airship and its ambient air as a “rigid body-fluid” system from an energy point of view. The added inertial, gravity, aerostatics, and dissipative forces are incorporated into the dynamics model, and are expressed as parameterized matrices in a common framework. Third, the validity of the proposed dynamics model is verified by comparing simulations with the dynamics model derived from Newton-Euler formulation.
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