The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Kajetan Nürnberger - One of the best experts on this subject based on the ideXlab platform.
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Active Control Objective Prioritization for High-Bandwidth Automatic Flight Path Control
Advances in Aerospace Guidance Navigation and Control, 2017Co-Authors: Erik Karlsson, Agnes Gabrys, Thaddäus Baier, Christoph Dörhöfer, Markus Hochstrasser, Christoph Krause, Patrick J. Lauffs, Nils C. Mumm, Kajetan Nürnberger, Lars PeterAbstract:Inherent Flight Path control objective conflicts arise when energy rate or Path curvature controls are saturated, precluding arbitrary Flight Path and speed target tracking, and arbitrary, concurrent vertical and lateral plane maneuvering. Flight envelope protection to protect airspeed and prevent loss of control are usually a last line of defense, and not an integrated strategy for smooth and deterministic control objective resolution during normal operation. In this paper, active energy rate and force distribution prioritizations, as integrated parts of the Flight Path controller of a modular Flight guidance and control system, are presented. The prioritizations allow speed or Flight Path angle maneuvering to be prioritized in case of saturated energy control, with automatic speed priority at the edges of the envelope in order to ensure the energy integrity of the aircraft, and lateral or vertical plane maneuvering in case of saturated transverse force control. The approach is validated using high-fidelity simulations and initial Flight testing.
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Development of an Automatic Flight Path Controller for a DA42 General Aviation Aircraft
Advances in Aerospace Guidance Navigation and Control, 2017Co-Authors: Erik Karlsson, Agnes Gabrys, Simon P. Schatz, Thaddäus Baier, Christoph Dörhöfer, Markus Hochstrasser, Christoph Krause, Patrick J. Lauffs, Nils C. Mumm, Kajetan NürnbergerAbstract:The development of an automatic Flight Path controller, as part of a modular automatic Flight guidance and control system, is presented, along with Flight test results using a DA42 M-NG flying testbed. The basic principle for the Flight Path controller is a reference model based dynamic inversion of the translational equations of motions, with pseudo-control hedging to account for inner loop dynamics and plant response deficits. The kinematic frame Flight Path commands are transformed into body-frame commands executed by inner loop and autothrust controllers for transverse and linear force control. Requirements and verification activities are briefly discussed. Flight test results demonstrates the feasibility of the Path control approach, with good tracking and disturbance performance.
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ICARCV - Automatic Flight Path control of an experimental DA42 general aviation aircraft
2016 14th International Conference on Control Automation Robotics and Vision (ICARCV), 2016Co-Authors: Erik Karlsson, Agnes Gabrys, Simon P. Schatz, Thaddäus Baier, Christoph Dörhöfer, Markus Hochstrasser, Christoph Krause, Patrick J. Lauffs, Nils C. Mumm, Kajetan NürnbergerAbstract:An automatic Flight Path controller, as part of a modular automatic Flight guidance and control system, is presented, along with initial Flight test results using a DA42 M-NG flying testbed. The basic principle for the Flight Path control is a reference model based dynamic inversion of the kinematic equations of motions, with pseudo-control hedging to account for inner loop dynamics and plant response deficits. The kinematic frame Flight Path commands are transformed into body-frame commands executed by inner loop and autothrust controllers for transverse and linear force control. Initial Flight test results are presented, demonstrating the feasibility of the Path control approach, with good tracking and disturbance performance already during early Flight testing.
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Automatic Flight Path control of an experimental DA42 general aviation aircraft
2016 14th International Conference on Control Automation Robotics and Vision (ICARCV), 2016Co-Authors: Erik Karlsson, Agnes Gabrys, Simon P. Schatz, Thaddäus Baier, Christoph Dörhöfer, Markus Hochstrasser, Christoph Krause, Patrick J. Lauffs, Nils C. Mumm, Kajetan NürnbergerAbstract:An automatic Flight Path controller, as part of a modular automatic Flight guidance and control system, is presented, along with initial Flight test results using a DA42 M-NG flying testbed. The basic principle for the Flight Path control is a reference model based dynamic inversion of the kinematic equations of motions, with pseudo-control hedging to account for inner loop dynamics and plant response deficits. The kinematic frame Flight Path commands are transformed into body-frame commands executed by inner loop and autothrust controllers for transverse and linear force control. Initial Flight test results are presented, demonstrating the feasibility of the Path control approach, with good tracking and disturbance performance already during early Flight testing.
Uwe Fechner - One of the best experts on this subject based on the ideXlab platform.
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Flight Path planning in a turbulent wind environment
Airborne Wind Energy, 2018Co-Authors: Uwe FechnerAbstract:To achieve a high conversion efficiency and at the same time robust control of a pumping kite power system it is crucial to optimize the three-dimensional Flight Path of the tethered wing. This chapter extends a dynamic system model to account for a realistic, turbulent wind environment and adds a Flight Path planner using a sequence of attractor points and turn actions. Path coordinates are calculated with explicit geometric formulas. To optimize the power output the Path is adapted to the average wind speed and the vertical wind profile, using a small set of parameters. The planner employs a finite state machine with switch conditions that are highly robust towards sensor errors. The results indicate, that the decline of the average power output of pumping kite power systems at high wind speeds can be mitigated. In addition it is shown, that reeling out towards the zenith after flying figure eight Flight maneuvers significantly reduces the traction forces during reel-in and thus increases the total efficiency.
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Flight Path control of kite power systems in a turbulent wind environment
2016 American Control Conference (ACC), 2016Co-Authors: Uwe Fechner, Roland SchmehlAbstract:Converting the traction power of kites into electricity can be a low cost solution for wind energy. A reliable and robust control system is considered to be crucial for the commercial success of the technology. The focus of this paper is the control of the Flight Path projected onto the unit sphere. The proposed algorithm is straightforward to implement because it uses mainly LPV and PID control components and is thus easy to certify by the authorities, it allows to define limits for the maximal turn rate to avoid sensor failures, and it allows to use a low gain in the feedback loop to be robust against control loop delays up to 200 ms. This is achieved by splitting the control of the Flight Path into two different modes of operation: Turn maneuvers and parts of the Flight Path, where the course angle is constant. During the turning maneuvers mainly feedforward control is used, therefore reducing stability problems. During the straight Flight Path segments feedback control in combination with Nonlinear Dynamic Inversion (NDI) is used and thus deviations from the planned Flight Path can be compensated. NDI is needed to compensate the effect of gravity on the turn rate, but also the changes of the steering sensitivity, depending on the apparent wind speed and the angle of attack. A dynamic 4-point model of the kite is used for the validation of the controller performance. The kite is flown in a turbulent 3D wind field using the Mann-model for modeling the turbulence. The results show a low tracking error even in very turbulent wind conditions and even in the presence of large sensor errors and control loop delays: At a turbulence intensity of 26.5% the elevation error was still lower than 1.5°.
Hua O. Wang - One of the best experts on this subject based on the ideXlab platform.
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3-D Flight Path Tracking Control for Unmanned Aerial Vehicles Under Wind Environments
IEEE Transactions on Vehicular Technology, 2019Co-Authors: Kazuo Tanaka, Motoyasu Tanaka, Yutoku Takahashi, Arimasa Iwase, Hua O. WangAbstract:This paper provides a new design framework for 3D Flight Path tracking control of unmanned aerial vehicles (UAVs) under wind environments. The new design framework simultaneously achieves the following three points: (i) 3D Path tracking error system representation using the Serret-Frenet frame under wind environments, (ii) guaranteed cost control, (iii) simultaneous stabilization by a single controller for different 3D Paths with a common interval parameter setting in the Serret-Frenet frame. To realize the three points, a Path tracking error system based on the 3D kinematic model of UAVs under wind environments is constructed in the Serret-Frenet frame. The Path tracking error system is exactly represented with the Takagi-Sugeno (T-S) fuzzy model in considered operation domains. As an advantage of the T-S fuzzy model construction, this paper considers a guaranteed cost controller design that minimizes the upper bound of a given performance function. The guaranteed cost controller design problem is cast in terms of linear matrix inequalities (LMIs). Thus, the designed controller guarantees not only the Path stabilization but also the guaranteed cost control even in Path tracking control for a given desired 3D Flight Path under wind environments. In addition, a simultaneous stabilization problem is also considered in terms of finding a common solution in a set of the LMIs. The simulation results show the utility of the proposed 3D Flight Path tracking control under wind environments.
Shuqing Zhang - One of the best experts on this subject based on the ideXlab platform.
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Three-dimensional Flight Path planning by artificial immune algorithm
Natural Computation (ICNC) 2010 Sixth International Conference on, 2010Co-Authors: Lifeng Liu, Shuqing ZhangAbstract:Artificial immune algorithm (AIA) is used for offline as well as online Path planning in this paper. Firstly, AIA is divided into three cases: 1. antibody is randomly selected to inoculate; 2. all antibodies are inoculated; 3. every antibody is inoculated, but inoculated location is selected at random. At the same time, we have simulated two kinds of threat uncertainties and one special occasion (no-fly-zone): changing the size of a certain kind of threat or increasing the number of unexpected threat. Based on above Flight Path planned, we adjust level Path to meet maximum turning angle restriction, and vertical track to normal acceleration and curvature constraint by slope restriction algorithm and curvature smoothing algorithm making practical steering possible. And we also reduced the redundant Path points (or frequent turning) to easy pilot manipulate and decrease the unsafe factors of Flight. In addition, 3 orders B-spline curve is utilized for representing 3D Path. At last, the simulated three-dimensional Flight Path by improved electric potential method and artificial immune algorithm are compared and the result is: artificial immune algorithm is not only feasible for searching three dimensional Path applications, but there is a great reduction of the computational time.
Erik Karlsson - One of the best experts on this subject based on the ideXlab platform.
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Active Control Objective Prioritization for High-Bandwidth Automatic Flight Path Control
Advances in Aerospace Guidance Navigation and Control, 2017Co-Authors: Erik Karlsson, Agnes Gabrys, Thaddäus Baier, Christoph Dörhöfer, Markus Hochstrasser, Christoph Krause, Patrick J. Lauffs, Nils C. Mumm, Kajetan Nürnberger, Lars PeterAbstract:Inherent Flight Path control objective conflicts arise when energy rate or Path curvature controls are saturated, precluding arbitrary Flight Path and speed target tracking, and arbitrary, concurrent vertical and lateral plane maneuvering. Flight envelope protection to protect airspeed and prevent loss of control are usually a last line of defense, and not an integrated strategy for smooth and deterministic control objective resolution during normal operation. In this paper, active energy rate and force distribution prioritizations, as integrated parts of the Flight Path controller of a modular Flight guidance and control system, are presented. The prioritizations allow speed or Flight Path angle maneuvering to be prioritized in case of saturated energy control, with automatic speed priority at the edges of the envelope in order to ensure the energy integrity of the aircraft, and lateral or vertical plane maneuvering in case of saturated transverse force control. The approach is validated using high-fidelity simulations and initial Flight testing.
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Development of an Automatic Flight Path Controller for a DA42 General Aviation Aircraft
Advances in Aerospace Guidance Navigation and Control, 2017Co-Authors: Erik Karlsson, Agnes Gabrys, Simon P. Schatz, Thaddäus Baier, Christoph Dörhöfer, Markus Hochstrasser, Christoph Krause, Patrick J. Lauffs, Nils C. Mumm, Kajetan NürnbergerAbstract:The development of an automatic Flight Path controller, as part of a modular automatic Flight guidance and control system, is presented, along with Flight test results using a DA42 M-NG flying testbed. The basic principle for the Flight Path controller is a reference model based dynamic inversion of the translational equations of motions, with pseudo-control hedging to account for inner loop dynamics and plant response deficits. The kinematic frame Flight Path commands are transformed into body-frame commands executed by inner loop and autothrust controllers for transverse and linear force control. Requirements and verification activities are briefly discussed. Flight test results demonstrates the feasibility of the Path control approach, with good tracking and disturbance performance.
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ICARCV - Automatic Flight Path control of an experimental DA42 general aviation aircraft
2016 14th International Conference on Control Automation Robotics and Vision (ICARCV), 2016Co-Authors: Erik Karlsson, Agnes Gabrys, Simon P. Schatz, Thaddäus Baier, Christoph Dörhöfer, Markus Hochstrasser, Christoph Krause, Patrick J. Lauffs, Nils C. Mumm, Kajetan NürnbergerAbstract:An automatic Flight Path controller, as part of a modular automatic Flight guidance and control system, is presented, along with initial Flight test results using a DA42 M-NG flying testbed. The basic principle for the Flight Path control is a reference model based dynamic inversion of the kinematic equations of motions, with pseudo-control hedging to account for inner loop dynamics and plant response deficits. The kinematic frame Flight Path commands are transformed into body-frame commands executed by inner loop and autothrust controllers for transverse and linear force control. Initial Flight test results are presented, demonstrating the feasibility of the Path control approach, with good tracking and disturbance performance already during early Flight testing.
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Dynamic Flight Path control coupling for energy and maneuvering integrity
2016 14th International Conference on Control Automation Robotics and Vision (ICARCV), 2016Co-Authors: Erik Karlsson, Agnes Gabrys, Simon P. Schatz, Florian HolzapfelAbstract:Traditional autopilots suffer from inherent Flight Path control objective conflict problems, as arbitrary Flight Path and speed targets cannot be maintained with saturated energy rate control. Elementary Flight envelope protections are typically introduced to protect airspeed and prevent loss of control, but rather as a "last line of defense", than as a mean of smooth and deterministic control objective resolution during normal operation. In this paper, an approach for active energy distribution prioritization and integrity protection, as integrated part of the Flight Path controller of a modular Flight guidance and control system, is presented. The approach allows speed or Flight Path angle maneuvering to be prioritized in case of saturated energy control, with automatic speed priority at the edges of the envelope in order to ensure the airspeed integrity of the aircraft. The approach is analyzed and validated using high-fidelity simulations of the full closed loop system for various conditions.
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Automatic Flight Path control of an experimental DA42 general aviation aircraft
2016 14th International Conference on Control Automation Robotics and Vision (ICARCV), 2016Co-Authors: Erik Karlsson, Agnes Gabrys, Simon P. Schatz, Thaddäus Baier, Christoph Dörhöfer, Markus Hochstrasser, Christoph Krause, Patrick J. Lauffs, Nils C. Mumm, Kajetan NürnbergerAbstract:An automatic Flight Path controller, as part of a modular automatic Flight guidance and control system, is presented, along with initial Flight test results using a DA42 M-NG flying testbed. The basic principle for the Flight Path control is a reference model based dynamic inversion of the kinematic equations of motions, with pseudo-control hedging to account for inner loop dynamics and plant response deficits. The kinematic frame Flight Path commands are transformed into body-frame commands executed by inner loop and autothrust controllers for transverse and linear force control. Initial Flight test results are presented, demonstrating the feasibility of the Path control approach, with good tracking and disturbance performance already during early Flight testing.