Results 41 to 50 of about 5,002,744 (342)

Resource Allocation and Trajectory Optimization for UAV-Enabled Multi-User Covert Communications

IEEE Transactions on Vehicular Technology, 2021
In this correspondence, covert air-to-ground communication is investigated to hide the wireless transmission from unmanned aerial vehicle (UAV). The warden's total detection error probability with limited observations is first analyzed.
Xu Jiang, Zhutian Yang, Nan Zhao, Yunfei Chen, Z. Ding, Xianbin Wang   +5 more
semanticscholar   +1 more source

A Survey on Low-Thrust Trajectory Optimization Approaches

Aerospace, 2021
In this paper, we provide a survey on available numerical approaches for solving low-thrust trajectory optimization problems. First, a general mathematical framework based on hybrid optimal control will be presented.
David Morante, Manuel Sanjurjo Rivo, M. Soler   +2 more
semanticscholar   +1 more source

Joints Trajectory Planning of Robot Based on Slime Mould Whale Optimization Algorithm

Algorithms, 2022
The joints running trajectory of a robot directly affects it’s working efficiency, stationarity and working quality. To solve the problems of slow convergence speed and weak global search ability in the current commonly used joint trajectory optimization
Xinning Li, Qin Yang, Hu Wu, Shuai Tan, Qun He, Neng Wang, Xianhai Yang   +6 more
doaj   +1 more source

Robust Low-Thrust Trajectory Optimization Using Convex Programming and a Homotopic Approach

IEEE Transactions on Aerospace and Electronic Systems, 2022
A robust algorithm to solve the low-thrust fuel-optimal trajectory optimization problem for interplanetary spacecraft is developed in this article.
A. Morelli, C. Hofmann, F. Topputo
semanticscholar   +1 more source

Approximate optimal atmospheric entry trajectories [PDF]

Guidance, Control and Flight Mechanics Conference, 1971
For a reentry glider, approximate solutions are found in closed form for the problem of maximizing a function of the terminal velocity, altitude, flight-path angle and heading angle subject to, at most, three terminal nonlinear constraints. The results given here extend the previous results in two important ways: (1) the second-order approximation of ...
JASON L. SPEYER, M. EDWARD WOMBLE
openaire   +1 more source

Research on Aerodynamic Force/Thrust Vector Combined Trajectory Optimization Method for Hypersonic Drones Based on Deep Reinforcement Learning

Actuators
This paper addresses the cruise range maximization problem for hypersonic drones by proposing a combined aerodynamic force/thrust vector trajectory optimization method.
Zijun Zhang, Yunfan Zhou, Leichao Yang, Wenzhong Jin, Jun Wang   +4 more
doaj   +1 more source

Trajectory Planning of Energy Consumption Optimal Redundant Manipulators with Constraints

Jixie chuandong, 2022
Aiming at the problem of how to reduce the complexity of trajectory optimization of redundant or super-redundant manipulators， a constrained energy consumption optimal manipulator trajectory planning method is proposed.
Yuanfei Zhou, Haitao Tang
doaj  

Optimal Trajectories for Hypervelocity Flight [PDF]

1989 American Control Conference, 1989
This paper discusses optimal trajectories for hypervelocity flight of interest in aeroassisted orbital transfer. Both coplanar orbital transfer and noncoplanar orbital transfer are studied. For these cases, the GEO- to-LEO transfer, the HEO-to-LEO transfer, and the LEO-to-LEO transfer are considered in connection with a spacecraft which is controlled ...
Miele, A., Lee, W. Y.
openaire   +2 more sources

Multi-stage global trajectory optimization for the overlapping shift of a seamless two-speed transmission using Legendre pseudo-spectral method

Advances in Mechanical Engineering, 2017
For a seamless two-speed transmission specially equipped in electric vehicles, the global trajectory optimization problem of the overlapping shift process with multiple stages and complex path/point constraints is investigated in this article.
Jie Ye, Kegang Zhao, Yanwei Liu, Xiangdong Huang, Huibin Lin   +4 more
doaj   +1 more source

Predicting Chronicity in Children and Adolescents With Newly Diagnosed Immune Thrombocytopenia at the Timepoint of Diagnosis Using Machine Learning‐Based Approaches

Pediatric Blood &Cancer, EarlyView.
ABSTRACT Objectives To identify predictors of chronic ITP (cITP) and to develop a model based on several machine learning (ML) methods to estimate the individual risk of chronicity at the timepoint of diagnosis. Methods We analyzed a longitudinal cohort of 944 children enrolled in the Intercontinental Cooperative immune thrombocytopenia (ITP) Study ...
Severin Kasser, Alice Bizeul, Meera Chitlur, Hugo Donato, Jelena Roganovic, Julia E. Vogt, Thomas Kühne   +6 more
wiley   +1 more source