A Shape-Based Approach For Low-Thrust Earth-Moon Trajectories Initial Design [0.03%]
一种基于形状特性的地-月低推力轨迹初步设计方法研究
Madhusudan Vijayakumar,Ossama Abdelkhalik
Madhusudan Vijayakumar
A Robust Finite Fourier Series (R-FFS) approach is developed for fast generation of Earth-Moon trajectories using continuous low thrust. Each component of the position vector is approximated using a finite Fourier series as a function of ti...
Real-Time Estimation of Bare-Airframe Frequency Responses from Closed-Loop Data and Multisine Inputs [0.03%]
闭环数据和多正弦输入的实时裸骨架频率响应估计
Jared A Grauer,Matthew J Boucher
Jared A Grauer
A method is presented for estimating frequency responses of multiple-input multiple-output bare-airframe dynamics from flight test data containing feedback control and/or mixing of control effectors. Orthogonal phase-optimized multisines ar...
Analytic Gradient Computation for Bounded-Impulse Trajectory Models Using Two-Sided Shooting [0.03%]
使用双向射影法计算有界脉冲轨迹模型的解析梯度
Donald H Ellison,Bruce A Conway,Jacob A Englander et al.
Donald H Ellison et al.
Many optimization methods require accurate partial derivative information in order to ensure efficient, robust, and accurate convergence. In this paper, analytic methods are developed for computing complex partial derivatives of two bounded...
Data Mining Approach to Poincaré Maps in Multi-Body Trajectory Design [0.03%]
数据挖掘在多体轨道设计中的庞加莱映射中的应用
Natasha Bosanac
Natasha Bosanac
Ping Lu
Ping Lu
The notion and the theory of constructing planetary powered descent guidance laws based on fractional polynomials are introduced. Along the way a new perspective to the classical Apollo powered descent guidance designs is gained. As a found...
John R Cooper,Paul M Rothhaar
John R Cooper
Project Link! is a NASA-led effort to study the feasibility of multi-aircraft aerial docking systems. In these systems, a group of vehicles physically link to each other during flight to form a larger ensemble vehicle with increased aerodyn...
An Automated Solution of the Low-Thrust Interplanetary Trajectory Problem [0.03%]
低推力行星间轨道问题的自动化求解方法研究
Jacob A Englander,Bruce A Conway
Jacob A Englander
Preliminary design of low-thrust interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the f...
Computational simulation of extravehicular activity dynamics during a satellite capture attempt [0.03%]
卫星捕获尝试期间出舱活动的计算仿真研究
G Schaffner,D J Newman,S K Robinson
G Schaffner
A more quantitative approach to the analysis of astronaut extravehicular activity (EVA) tasks is needed because of their increasing complexity, particularly in preparation for the on-orbit assembly of the International Space Station. Existi...
Closed-loop, estimator-based model of human posture following reduced gravity exposure [0.03%]
一种基于估计的人体姿态模型：微重力环境适应性的闭环模型
D J Newman,K U Schultz,J L Rochlis
D J Newman
A computational and experimental method is employed to provide an understanding of a critical human space flight problem, posture control following reduced gravity exposure. In the case of an emergency egress, astronauts' postural stability...
G L Zacharias,A X Miao,R Warren
G L Zacharias
Human computational vision models that attempt to account for the dynamic perception of egomotion and relative depth typically assume a common three-stage process: first, compute the optical flow field based on the dynamically changing imag...