Motion Prediction of a Free-Floating Noncooperative Target Considering J2 Perturbation

2021 ◽  
Vol 16 (5) ◽  
Author(s):  
Qishuai Wang ◽  
Bangzhao Zhou ◽  
Xiaofeng Liu ◽  
Guoping Cai
Keyword(s):  
High Precision ◽  
Unscented Kalman Filter ◽  
Great Influence ◽  
Prediction Method ◽  
Motion Prediction ◽  
Dynamic Parameters ◽  
J2 Perturbation ◽  
Long Time ◽  
Core Idea ◽  
Precision Motion

Abstract Motion prediction of space noncooperative target is an important issue for spacecraft on-orbit service. After obtaining high-precision motion prediction results, the chaser can efficiently plan a motion trajectory to approach the target and then capture it. In this paper, a motion prediction method considering J2 perturbation is proposed for a free-floating noncooperative target. The core idea of this method is to identify dynamic parameters of the target, and then realize the motion prediction through a dynamic model of the target that considering J2 perturbation. In the identification of the dynamic parameters, inertia parameters of the target are preliminarily identified first, then a noise-adaptive unscented Kalman filter (UKF) is applied to roughly identify the dynamic parameters, and finally, the identification precision is further improved through optimization. At the end of this paper, the significance of considering J2 perturbation is demonstrated by numerical simulations, and the effectiveness of the proposed method is verified. Simulation results indicate that J2 perturbation has a great influence on the motion prediction of the target and that the proposed method can yield long-time high-precision motion prediction results. Specifically, under the simulation conditions of this paper, the predicted time obtained by the proposed method is longer than 200 s, and the errors of the motion prediction results of the target's attitude and position are less than 2 deg and 0.02 m, respectively.

Ultra‐Sensitive and Stretchable Ionic Skins for High‐Precision Motion Monitoring

2021 ◽  
pp. 2010199
Author(s):  
Jeong Hui Kim ◽  
Kyung Gook Cho ◽  
Dae Hyun Cho ◽  
Kihyon Hong ◽  
Keun Hyung Lee
Keyword(s):  
High Precision ◽  
Precision Motion

scholarly journals Compensation of Hysteresis in Hybrid Reluctance Actuator for High-Precision Motion

2019 ◽  
Vol 52 (15) ◽  
pp. 477-482 ◽  
Author(s):  
Francesco Cigarini ◽  
Shingo Ito ◽  
Julian Konig ◽  
Andreas Sinn ◽  
Georg Schitter
Keyword(s):  
High Precision ◽  
Precision Motion

SHIP MOTIONS DURING REPLENISHMENT AT SEA OPERATIONS IN HEAD SEAS

2021 ◽  
Vol 152 (A4) ◽  
Author(s):  
G Thomas ◽  
T Turner ◽  
T Andrewartha ◽  
B Morris
Keyword(s):  
Experimental Study ◽  
Green Function ◽  
Prediction Method ◽  
Ship Motion ◽  
Motion Prediction ◽  
Ship Motions ◽  
Forward Speed ◽  
Theoretical Predictions ◽  
Relative Separation ◽  
Replenishment At Sea

During replenishment at sea operations the interaction between the two vessels travelling side by side can cause significant motions in the smaller vessel and affect the relative separation between their replenishment points. A study into these motions has been conducted including theoretical predictions and model experiments. The model tests investigated the influence of supply ship displacement and longitudinal separation on the ships’ motions. The data obtained from the experimental study has been used to validate a theoretical ship motion prediction method based on a 3-D zero-speed Green function with a forward speed correction in the frequency domain. The results were also used to estimate the expected extreme roll angle of the receiving vessel, and the relative motion between the vessels, during replenishment at sea operations in a typical irregular seaway. A significant increase in the frigate’s roll response was found to occur with an increase of the supply ship displacement, whilst a reduction in motion for the receiving vessel resulted from an increase in longitudinal separation between the vessels. It is proposed that to determine the optimal vessel separation it is vital that the motions of the vessels are not considered in isolation and all motions need to be considered for both vessels simultaneously.

scholarly journals Improved Model of Scheduling Algorithm

2018 ◽  
pp. 104-106
Author(s):  
Artur Vardanyan
Keyword(s):  
High Performance ◽  
Cluster Computing ◽  
Scheduling Algorithm ◽  
Great Influence ◽  
Cluster Management ◽  
Task Scheduling Algorithm ◽  
Long Time ◽  
Improved Model ◽  
First In First Out

Cluster computing is becoming increasingly practical for high performance computing research and development. A computer cluster is a set of connected computers that work together so that, they can be viewed as a single system. Clusters offer a scalable means of linking computers together to provide an expansive environment for hosting enterprise applications. As the number of nodes in cluster configurations grows, the cluster administration becomes more challenging. We need to study the challenges of cluster management and to provide a solution. To have an effective cluster management we need to have an effective task scheduling algorithm. With the explosive growth of information, the demand on computing is sharply increasing. Due to a large number of computing tasks, the scheduling algorithm is an important part of cluster computing and has a great influence on the quality of claster service. In cluster computing, some large tasks may occupy too many resources and some small tasks may wait for a long time based on First-In-First-Out (FIFO) scheduling algorithm. This paper provides an overview of an improved scheduling algorithm that shortens the execution time of tasks and increases the resource utilization.

scholarly journals The Influence of Cultural Traditions on Sound Design Techniques in Japanese Cinema. Sound Effects and Music

2018 ◽  
Vol 10 (1) ◽  
pp. 92-105
Author(s):  
Elena A Rusinova ◽  
Elizaveta M Habchuk
Keyword(s):  
Film Theory ◽  
Great Influence ◽  
Sound Design ◽  
The West ◽  
Cultural Traditions ◽  
Japanese Cinema ◽  
Musical Tradition ◽  
Long Time ◽  
Russian Cinema ◽  
Artistic Image

For a long time, Japanese cinema has been developing separately, mastering the specifics of the new art, which came from the West, and at the same time trying to solve within its framework the problem of "national identity". However, since the 1950s, Japanese cinema has become widely known abroad and is gaining recognition in the West. The present day no one doubts the huge contribution of Japanese filmmakers to the history of world cinema. Nevertheless, the study of Japanese cinema in Russian cinema theory still remains the prerogative of a few professionals who know the Japanese language and are closely acquainted with the Japanese mentality, culture and art, which exert a great influence on the artistic features of Japanese screen art. But in order to even more imbued with the originality of the approach to creating an artistic image in Japanese cinema, it is necessary to draw attention to one of the most important components of its structure, namely, the sound aspect, insufficiently studied in film theory. The novelty of the article is that it analyzes and classifies the sound features of some Japanese movies created in the second half of the 20th - beginning of the 21st centuries, in which the influence of traditional culture manifests itself quite clearly, but at the same time the presence of elements of the Western musical tradition is also noticeable, which reflects to a certain extent the process of transculturalism in cinema that is actual nowadays.

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