Autonomous Take-Off and Flight of a Tethered Aircraft for Airborne Wind Energy
Politecnico di Milano（米兰理工大学）；ABB Switzerland Ltd.（瑞士ABB有限公司）
Lorenzo Fagiano, Eric Nguyen-Van, Felix Rager, Stephan Schnez, Christian Ohler
备注：
This is the pre-print of a paper accepted for publication on the IEEE Transactions on Control systems Technology and is subject to IEEE Copyright. doi: 10.1109/TCST.2017.2661825
A control design approach to achieve fully autonomous take-off and flight maneuvers with a tethered aircraft is presented and demonstrated in real-world flight tests with a small-scale prototype. A ground station equipped with a controlled winch and a linear motion system accelerates the aircraft to take-off speed and controls the tether reeling in order to limit the pulling force. This setup corresponds to airborne wind energy systems with ground-based energy generation and rigid aircrafts. A simple model of the aircraft's dynamics is introduced and its parameters are identified from experimental data. A model-based, hierarchical feedback controller is then designed, whose aim is to manipulate the elevator, aileron and propeller inputs in order to stabilize the aircraft during the take-off and to achieve figure-of-eight flight patterns parallel to the ground. The controller operates in a fully decoupled mode with respect to the ground station. Parameter tuning and stability/robustness aspect are discussed, too. The experimental results indicate that the controller is able to achieve satisfactory performance and robustness, notwithstanding its simplicity, and confirm that the considered take-off approach is technically viable and solves the issue of launching this kind of airborne wind energy systems in a compact space and at low additional cost.
This paper proposes and simulates vertical airborne wind energy (AWE) farms based on multi-aircraft systems with high power density (PD) per ground area. These farms consist of many independently ground located systems that are flying at the same inclination angle, but with different tether lengths, such that all aircraft fly in a large planar elliptical area that is vertical to the tethers. The individual systems are assigned non-overlapping flight cylinders depending on the wind direction. Detailed calculations that take into account Betz' limit, assuming a cubically averaged wind power dens…
Geometric Inverse Flight Dynamics on SO(3) and Application to Tethered Fixed-Wing Aircraft
Robotics and Mechatronics lab, Faculty of Electrical Engineering, Mathematics & Computer Science, University of Twente（代尔夫特理工大学机器人与机电实验室，电气工程、数学与计算机科学学院，代尔夫特理工大学）；Department of Computer, Control and Management Engineering, Sapienza University of Rome（罗马大学计算机、控制与管理工程系，罗马萨皮恩扎大学）
A quaternion-based model for optimal control of the SkySails airborne wind energy system
SkySails GmbH（SkySails有限公司）；Systems Control and Optimization Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg（弗赖堡大学微系统工程研究所（IMTEK）系统与优化控制实验室）；Department ESAT (STADIUS/OPTEC), KU Leuven University（荷语鲁汶大学ESAT系（STADIUS/OPTEC））
The control design of an airborne wind energy system with rigid aircraft, vertical take-off and landing, and pumping operation is described. A hierarchical control structure is implemented, in order to address all operational phases: take-off, transition to power generation, pumping energy generation cycles, transition to hovering, and landing. Control design at all hierarchical levels is described. The design approach is conceived and developed with real-world applicability as main driver. Aircraft design considerations in light of system maneuverability are presented, too, as well as three p…
The design of aircraft collision avoidance algorithms is a subtle but important challenge that merits the need for provable safety guarantees. Obtaining such guarantees is nontrivial given the unpredictability of the interplay of the intruder aircraft decisions, the ownship pilot reactions, and the subtlety of the continuous motion dynamics of aircraft. Existing collision avoidance systems, such as TCAS and the Next-Generation Airborne Collision Avoidance System ACAS X, have been analyzed assuming severe restrictions on the intruder's flight maneuvers, limiting their safety guarantees in real-…
This magazine investigates the potential enhancement of the data throughput of ground users by integrating ground base stations (GBS) with air stations, such as balloon, airborne, and satellite. The objective is to establish dynamic bi-directional wireless services (i.e., uplink and downlink) for ground users in congested and remote areas. The proposed integration involves satellite, high-altitude platforms (HAPs), and tethered balloons (TBs) in the exosphere, stratosphere, and troposphere, respectively, for better altitude reuse coupled with emerging optical or other high-frequency directiona…
Airborne wind energy (AWE) systems are tethered flying devices that harvest wind resources at higher altitudes which are not accessible to conventional wind turbines. In order to become a viable alternative to other renewable energy technologies, AWE systems are required to fly reliably for long periods of time without manual intervention while being exposed to varying wind conditions. In the present work a methodology is presented, which augments an existing baseline controller with a prediction and prevention methodology to improve the resilience of the controller against these external dist…
