Thrust Vector Orientation in Pilot-Controlled Lunar Landings

1965 ◽  
Vol 2 (5) ◽  
pp. 816-817 ◽  
Author(s):  
L. KEITH BARKER ◽  
M. J. QUEIJO
Keyword(s):  
Thrust Vector ◽  
Vector Orientation ◽  
Lunar Landings

scholarly journals Use of the Lyapunov Functions for Calculating the Locally Optimal Control of a Thrust Vector during Low-Thrust Interorbital Transfer

2021 ◽  
Vol 59 (3) ◽  
pp. 212-221
Author(s):  
R. V. Yelnikov
Keyword(s):  
Optimal Control ◽  
Lyapunov Functions ◽  
Electric Propulsion ◽  
Control Algorithm ◽  
Control Technique ◽  
Control Algorithms ◽  
Low Thrust ◽  
The Maximum Principle ◽  
Thrust Vector ◽  
Vector Orientation

Abstract— This paper presents a method for locally optimal control of the thrust vector of the electric propulsion system (EPS) for a spacecraft that performs a multiturn interorbital transfer from the initial elliptical orbit into a geostationary orbit (GSO). The control represents the time dependences of the angles that characterize the EPS thrust vector orientation in space. Here, it is assumed that the EPS is always on. The proposed control algorithm belongs to the class of feedback control algorithms and is based on using the Lyapunov functions. Numerical examples are presented, which characterize the operability of the proposed control technique. Considerable attention is paid to the comparison of given solutions with the optimal solutions obtained within the framework of the maximum principle formalism.

Radiation-Induced Precipitation in Ti-6A1-4V

1980 ◽  
Vol 38 ◽  
pp. 154-155
Author(s):  
J. E. O'Neal ◽  
S. M. L. Sastry ◽  
J. W. Davis
Keyword(s):  
Dark Field ◽  
Dislocation Loops ◽  
Beta Titanium Alloy ◽  
Defect Clusters ◽  
Weak Beam ◽  
Beta Titanium ◽  
Small Defect ◽  
Radiation Induced ◽  
Vector Orientation ◽  
Defect Microstructures

The radiation-induced defect structure and nonequilibrium phase precipitation were studied in T1-6A1-4V (an alpha-beta titanium alloy), irradiated at 450 ± 30°C in row VII of the EBR-II to a fluence of 3.0 × 1021 neutrons/cm2 (En > 0.1 MeV). The Irradiation-induced defect microstructures were examined using bright-field, conventional dark-field, and weak-beam dark-field techniques. The nature of dislocations and dislocation loops was determined by standard-contrast experiments under two-beam conditions, and the small defect clusters were identified using the line-of-contrast criterion and black-white vector orientation criterion.

scholarly journals Closed-loop actuator identification for Brazilian Thrust Vector Control development

2016 ◽  
Vol 49 (17) ◽  
pp. 468-473 ◽  
Author(s):  
Timo Wekerle ◽  
Euler Gonçalves Barbosa ◽  
César Moura Batagini ◽  
Luís E.V. Loures da Costa ◽  
Luís Gonzaga Trabasso
Keyword(s):  
Vector Control ◽  
Closed Loop ◽  
Thrust Vector Control ◽  
Thrust Vector
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