Efficient Six Degree of Freedom Aircraft Trajectory Optimization with Application to Dynamic Soaring

2012 ◽  
Author(s):  
Tristan Flanzer ◽  
Roberto Bunge ◽  
Ilan Kroo
Keyword(s):  
Trajectory Optimization ◽  
Degree Of Freedom ◽  
Dynamic Soaring ◽  
Aircraft Trajectory ◽  
Six Degree Of Freedom

Trajectory optimisation of six degree of freedom aircraft using differential flatness

2018 ◽  
Vol 122 (1257) ◽  
pp. 1788-1810 ◽  
Author(s):  
P. Elango ◽  
R. Mohan
Keyword(s):  
Inverse Problem ◽  
Inverse Problems ◽  
Computational Efficiency ◽  
Degree Of Freedom ◽  
Differential Flatness ◽  
Thrust Vectoring ◽  
Dynamic Soaring ◽  
Six Degree Of Freedom ◽  
Control Surfaces ◽  
Trajectory Optimisation

ABSTRACTThe flatness of a six-degree-of-freedom (6DoF) aircraft model with conventional control surfaces – aileron, flap, rudder and elevator, along with thrust vectoring ability is established in this work. Trajectory optimisation of an aircraft can be cast as an inverse problem where the solution for control inputs that yield desired trajectories for certain states is sought. The solution to the inverse problems for certain systems is made tractable when they exhibit differential flatness. Flatness-based trajectory optimisation has a significant advantage over an equivalent collocation-based method in terms of computational efficiency and viability for real-time implementation. An application for the flatness of 6DoF aircraft is shown in the trajectory optimisation for dynamic soaring, and its connection with an equivalent 3DoF flatness-based implementation is also brought out. The results are compared with that from a collocation-based approach.

scholarly journals Exploration of high-altitude dynamic soaring based on six-degree-of-freedom model

2021 ◽  
Vol 39 (4) ◽  
pp. 703-711
Author(s):  
Siqi Liu ◽  
Junqiang Bai
Keyword(s):  
High Altitude ◽  
Wind Field ◽  
Degree Of Freedom ◽  
Field Energy ◽  
Dynamics Model ◽  
Wind Fields ◽  
Sideslip Angle ◽  
Dynamic Soaring ◽  
Flight Dynamics Model ◽  
Six Degree Of Freedom

Dynamic soaring is an emerging flight range-extension technology that effectively reduces UAV's energy consumption by deriving wind energy from lateral gradient wind fields. Comparing with the small UAV's near the surface, the application of dynamic soaring technology in the high-altitude long-endurance flight requires the additional consideration of the influence of sustained side wind, the influence of the sideslip angle cannot be ignored. This puts higher requirements on the flight dynamics model. In this paper, the dynamic model for the high-altitude dynamic soaring based on the six-degree-of-freedom equation is modeled to replace the traditional mass point model; the energy change principle of the high-altitude dynamic gliding is derived; the effect of the high-altitude wind field on the dynamic soaring UAV is analyzed; and the way to get optimal wind field energy acquisition and energy saving efficiency are analyzed. The results show that the dynamics model based on the six-degree-of-freedom equation can more realistically reflect at high altitude; the application of dynamic soaring can effectively improve the range of the high-altitude UAV; the wind direction at high-altitude wind field has a significant effect on the dynamic soaring efficiency.

Iterative feedback control based on frequency response model for a six-degree-of-freedom micro-vibration platform

2021 ◽  
pp. 107754632199731
Author(s):  
He Zhu ◽  
Shuai He ◽  
Zhenbang Xu ◽  
XiaoMing Wang ◽  
Chao Qin ◽  
...  
Keyword(s):  
Feedback Control ◽  
Frequency Response ◽  
Control Strategy ◽  
Degree Of Freedom ◽  
Small Displacement ◽  
Response Model ◽  
Parameter Uncertainties ◽  
Micro Vibration ◽  
Six Degree Of Freedom ◽  
Iterative Feedback

In this article, a six-degree-of-freedom (6-DOF) micro-vibration platform (6-MVP) based on the Gough–Stewart configuration is designed to reproduce the 6-DOF micro-vibration that occurs at the installation surfaces of sensitive space-based instruments such as large space optical loads and laser communications equipment. The platform’s dynamic model is simplified because of the small displacement characteristics of micro-vibrations. By considering the multifrequency line spectrum characteristics of micro-vibrations and the parameter uncertainties, an iterative feedback control strategy based on a frequency response model is designed, and the effectiveness of the proposed control strategy is verified by performing integrated simulations. Finally, micro-vibration experiments are performed with a 10 kg load on the platform. The results of these micro-vibration experiments show that after several iterations, the amplitude control errors are less than 3% and the phase control errors are less than 1°. The control strategy presented in this article offers the advantages of a simple algorithm and high precision and it can also be used to control other similar micro-vibration platforms.

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