检索结果-内蒙古大学图书馆

Covariance Estimation and Gaussianity Assessment for State and Measurement Noise

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2020年第1期43卷 132-139页

作者： Dunik, Jindrich Kost, Oliver Straka, Ondrej Blasch, Erik Univ West Bohemia Dept Cybernet Univ 8 Plzen 30614 Czech Republic US Air Force Res Lab Rome NY 13441 USA

来源：评论

学校读者我要写书评

暂无评论

Landing Guidance Strategy of Space Rider

引用

JOURNAL OF SPACECRAFT AND ROCKETS 2021年第4期58卷 1220-1231页

作者： Figueroa-Gonzalez, Antonio Cacciatore, Francesco Haya-Ramos, Rodrigo SENER Aeroesp SA Adv Syst & Avion Div Severo Ochoa 4 Madrid 28760 Spain

Space Rider is the European program proposed to develop an affordable and sustainable reusable space transportation system to enable access to and return from space. To procure a safe and accurate landing, Space Rider will use a large deployable parafoil to fly autonomously upon the landing site. The landing guidance algorithm is based on two preselected waypoints and enables the system to reach the target landing site with high accuracy and being adaptive to wind knowledge errors, turbulence, and uncertainties on the main characteristics of the system, such as aerodynamics, sensors, and actuator parameters. The core of the landing guidance strategy is the so-called quasi-optimal time algorithm, responsible for the terminal guidance and energy management exiting. This algorithm minimizes the difference between the time to go and the estimated duration of the terminal maneuvers to guarantee an accurate landing also in the presence of strong winds. This paper presents the guidance strategy and demonstrates the feasibility of the design by Monte Carlo analysis of the Space Rider landing using a six-degree-of-freedom parafoil-payload model. The design presented in this work successfully passed the Critical Design Review of the Space Rider guidance, navigation, and control subsystem in December 2019.

关键词： Parafoil Terminal Guidance Energy Management Monte Carlo Simulation Aerodynamic Coefficients navigation algorithm Six Degree of Freedom Onboard Sensors Space Transportation System Actuators

来源：评论

学校读者我要写书评

暂无评论

A Novel Infrared navigational algorithm for Autonomous Robots

A Novel Infrared Navigational Algorithm for Autonomous Robot...

引用

IEEE International Conference on Artificial Intelligence and Information Systems (ICAIIS)

作者： Doumbia, Mamadou Cheng, Xu Chen, Lipei Hunan Univ Sch Comp Sci & Elect Engn Changsha 420082 Peoples R China

ISBN: (数字)9781728165905

ISBN: (纸本)9781728165905

This paper contains a hybridization technique of an Odometer (Odom) and an Inertial navigation System (INS). The originality lies in the formulation of the odometer integrated by a Novel Infrared navigational algorithm (NIRNA) to build the system (Odom/INS) proposed. NIRNA, an algorithm for sensor fusion and navigation, is presented and its integration introduced to build Odom/INS system. In addition, the kinematic of the 4 wheeled mobile robot is study to consider two localization techniques based on (Inertial Measurement Units (IMU) and Odometer). The whole system built integrates the two localization techniques and use an Integrated Kalman Filter (IKF) as data fusion module in order to improve the estimated output of the whole system. Two simulation tests are conducted to evaluate the built system's performance. As fusion algorithm, Unscented Kalman Filter (UKF) and Extended Kalman Filter (EKF) are used (in turn) in the IKF module to investigate the robustness and accuracy of the built hybrid system and later compare their implementation results. The simulation results show that the proposed system is feasible and reliable and its implementation with NIRNA outperforms that of some existent navigation algorithms such as HCTNay. That is confirmed by the resulting results that the implementation with NIRNA presents higher accuracy estimation and lower meansquare error (MSE) for mobile robot state than for instance, the implementation with HCTNay.

关键词： Odometry INS Sensor fusion navigation algorithm Mobile robot

来源：评论

学校读者我要写书评

暂无评论

Hardware-in-the-Loop Testing for Suborbital Flights of the Safe and Precise Landing Integrated Capabilities Evolution (SPLICE) Project Technologies

Hardware-in-the-Loop Testing for Suborbital Flights of the S...

引用

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Rutishauser, David K. Tse, Teming NASA Johnson Space Ctr Houston TX 77058 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

The Safe and Precise Landing Integrated Capabilities Evolution (SPLICE) project continues NASA's extensive heritage of precision navigation and hazard avoidance for landing technology development. These technologies support human and robotic exploration, providing the capabilities to perform planetary landings accurately to desired sites of interest, and complete the landings safely despite challenging terrain. The SPLICE project is developing sensor systems, navigation algorithms and techniques, and computing resources that will be tested as an integrated Precision Landing and Hazard Avoidance (PL&HA) system in the coming year on a suborbital rocket flight provided by a commercial company. This partnership resulted from a NASA Tipping Point Solicitation, designed to utilize industry-developed space technologies for the demonstration of NASA capabilities to significantly advance their maturity. To this end, SPLICE avionics and software/simulation teams are developing a Hardware-in-the-Loop (HWIL) simulation capability to provide a development, integration, and test and verification platform for the SPLICE payload suborbital flight configuration. Key elements of this HWIL platform are (1) the Descent and Landing Computer (DLC), which integrates all the SPLICE technologies and provides the computational capabilities for the system, (2) the core Flight System cFS, an agency investment in a flight software framework, (3) the TRICK simulation, another agency investment in a simulation framework, (4) models for the flight vehicle, navigation sensors, and environment, and (5) the Guidance, navigation, and Control algorithms and software that define the PL&HA capabilities for SPLICE.

关键词： Suborbital Flights Sensor Technology navigation algorithm Avionics Software Computing Resources Rocket Flight Space Technology Control algorithm Flight Vehicle Inertial Measurement Unit

来源：评论

学校读者我要写书评

暂无评论

Autonomous Guidance and Flight Control on a Partial-Authority Black Hawk Helicopter

Autonomous Guidance and Flight Control on a Partial-Authorit...

引用

AIAA Aviation Forum

作者： Takahashi, Marc D. Fujizawa, Brian T. Lusardi, Jeffery A. Whalley, Matthew S. Goerzen, Chad L. Schulein, Gregory J. Mielcarek, Nathan L. Archdeacon, John L. Cleary, Mark J. Carr, James P. Waldman, David W. US Army Combat Capabil Dev Command Aviat & Missile Ctr Moffett Field CA 94035 USA San Jose State Res Fdn San Jose CA 23604 USA Univ Space Res Assoc USRA Moffett Field CA 94035 USA ASRC Fed Res & Technol Solut Moffett Field CA 94035 USA US Army Combat Capabil Dev Command Aviat & Missile Ctr Ft Eustis VA 23604 USA

ISBN: (数字)9781624105982

ISBN: (纸本)9781624105982

This paper describes an autonomous guidance and flight control system that was integrated and flight-tested on a partial-authority Black Hawk helicopter. This effort was part of the Degraded Visual Environment Mitigation program, whose objective is to provide all weather capability for U.S. Army rotorcraft operations. The guidance and flight-control system software were previously flight tested on a full-authority helicopter, and for this work, was adapted to fly on a partial-authority helicopter. The main autonomy components of the system consist of the Risk Minimizing Obstacle Field navigation algorithm, Safe Landing Area Determination algorithm, and the Integrated Cueing Environment. These components provide reactive avoidance guidance, landing site selection, and pilot situational awareness for degraded visual environments. To test the system, a LADAR was used as a surrogate-ranging device in lieu of an all-weather sensor system that was concurrently under development for the program. The autonomous partial-authority flight control system provides a fully stabilized path-following capability that is directed with a series of waypoints or flight-path vector commands. This paper describes the control system, its performance, and how it was adapted to a partial-authority system that is typical of current U.S. Army fleet helicopters. The autonomy software and human interface components are also described. Flight test results are presented of the fully integrated system navigating through terrain, selecting landing sites, and autonomously landing. Analysis is presented that compares partial-authority results to previously collected full-authority results.

关键词： Helicopters Flight Control System Test Pilots Flight Testing Control Systems Rotorcrafts navigation algorithm Position Sensors Obstacle Avoidance Landing Zone

来源：评论

学校读者我要写书评

暂无评论

Toward Autonomous In-flight Docking of Unmanned Multi-rotor Aerial Vehicles

Toward Autonomous In-flight Docking of Unmanned Multi-rotor ...

引用

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Rocha, Ryan A. Robinson, Stephen K. Univ Calif Davis Mech & Aerosp Engn Davis CA 95616 USA Univ Calif Davis Dept Mech & Aerosp Engn Davis CA 95616 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

The aim of this research was to develop a cost effective, low complexity and off-the-shelf system for autonomous in-flight docking of unmanned, battery-powered MAVs using only onboard sensors. The robotic system presented herein consists of two MAVs, a computer vision system and a docking mechanism. The docking MAV is responsible for performing the docking maneuver, while the carrier MAV holds position and receives the docking MAV. The docking mechanism consists of a rigid mast attached to the top of the carrier MAV. The vision system's camera is at the top of the mast, pointed along the z-direction of the carrier MAV. The frame of the docking MAV is ring-shaped to fit over the mast. The ring-shaped frame of the docking MAV is surrounded with LED (light-emitting diode) fiducial markers used by the vision system. A simulation was constructed in order to model the system and develop the detection, tracking and navigation algorithms. The algorithms were shown to be successful in simulation. The docking MAV's ability to hold its position over the center of the camera was tested using only GPS and the performance of that test was compared to a similar test using the computer vision system. The use of the computer vision system reduced the root-mean-square error of the MAV's position hold by 89% (0.73 m to 0.09 m) while also reducing its time spent outside of a desired horizontal radial limit of 0.1 m to 22% from 95%. These results suggest that this system is a viable approach to an in-flight docking system.

关键词： Autonomous Flight Computer Vision navigation algorithm Image Processing Onboard Sensors Downwash Quadrotor Flight Testing Yaw Control Flight Control System

来源：评论

学校读者我要写书评

暂无评论

Development of Probability Fields for Collision Avoidance

Development of Probability Fields for Collision Avoidance

引用

AIAA Aviation Forum

作者： Williams, Edwin A. Jin, Yan Schulze, P. Chase Syst Technol Inc Engn Serv Hawthorne CA 90250 USA Univ Southern Calif Aerosp & Mech Engn Los Angeles CA 90089 USA

ISBN: (数字)9781624105982

ISBN: (纸本)9781624105982

Standard Guidance, navigation, and Control (GN&C) systems take state data from a navigation system and create a trajectory that minimizes some a-priori determined cost function. Previous work has been done to show the effectiveness of using risk as the sole objective function. However, this previous work used Poisson distributions and historical estimates to achieve this goal. In this paper we present the underlying statistics of a situation-risk assessment (SRA) method contained within the intelligent situation assessment and collision avoidance (iSC) platform. The SRA method uses data clustering, and pattern recognition to create a historical-based estimate of guidance probabilities. These are then used in data driven, dynamic models to create future probability fields of the situation. The paper ends with an example creating a command decision probability function for a congested urban airspace environment.

关键词： Probability Density Functions Airspace navigation algorithm Unmanned Aircraft System Urban Air Mobility Guidance System Data Analysis Air Vehicle Autonomous Systems Systems Engineering

来源：评论

学校读者我要写书评

暂无评论

Unrealnavigation: Simulation Software for testing SLAM in Virtual Reality

UnrealNavigation: Simulation Software for testing SLAM in Vi...

引用

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Bettens, Anne Morrell, Benjamin Coen, Mauricio McHenry, Neil Wu, Xiaofeng Gibbens, Peter Chamitoff, Gregory Univ Sydney Sydney NSW 2006 Australia Texas A&M Univ College Stn TX 77840 USA Univ Newcastle Callaghan NSW 2308 Australia

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

We present Unrealnavigation;an integrated software platform for testing Simultaneous Localization and Mapping (SLAM) algorithms for autonomous robotic navigation. The framework, which is part of a Virtual Reality simulation in space environments is designed to allow rapid testing of autonomous navigation algorithm components. The architecture is designed with a plug-and-play style adaptability in mind, allowing for a wide range of uses and rapid development. Two approaches to SLAM will be demonstrated in the novel simulation framework, utilizing a game development engine, Unreal, connected by the Robotic Operating System (ROS). Comparison of these two algorithms was enabled through the simulation framework created. The different approaches authenticate the ability to integrate a holistic algorithm system or separate components into the framework.

关键词： Simultaneous Localization and Mapping Simulation Software Autonomous navigation System Space Environment Operating Systems Robots navigation algorithm Closed Loop System Asteroids Path Planning

来源：评论

学校读者我要写书评

暂无评论

Directed, cylindric and radial Brownian webs

引用

ELECTRONIC JOURNAL OF PROBABILITY 2019年第none期24卷 1-48页

作者： Coupier, David Marckert, Jean-Francois Viet Chi Tran Univ Valenciennes CNRS LAMAV EA 4015 F-59313 Valenciennes 9 France Univ Bordeaux CNRS LaBRI UMR 5800 351 Cours Liberat F-33405 Talence France Univ Lille CNRS Lab P Painleve Dept MathUMR 8524 F-59000 Lille France

The Brownian web (BW) is a collection of coalescing Brownian paths (W-(x,W-t), (x, t) is an element of R-2) indexed by the plane. It appears in particular as continuous limit of various discrete models of directed forests of coalescing random walks and navigation schemes. Radial counterparts have been considered but global invariance principles are hard to establish. In this paper, we consider cylindrical forests which in some sense interpolate between the directed and radial forests: we keep the topology of the plane while still taking into account the angular component. We define in this way the cylindric Brownian web (CBW), which is locally similar to the planar BW but has several important macroscopic differences. For example, in the CBW, the coalescence time between two paths admits exponential moments and the CBW as its dual contain each a.s. a unique bi-infinite path. This pair of bi-infinite paths is distributed as a pair of reflected Brownian motions on the cylinder. Projecting the CBW on the radial plane, we obtain a radial Brownian web (RBW), i.e. a family of coalescing paths where under a natural parametrization, the angular coordinate of a trajectory is a Brownian motion. Recasting some of the discrete radial forests of the literature on the cylinder, we propose rescalings of these forests that converge to the CBW, and deduce the global convergence of the corresponding rescaled radial forests to the RBW. In particular, a modification of the radial model proposed in Coletti and Valencia is shown to converge to the CBW.

关键词： Brownian web navigation algorithm random spanning forests weak convergence of stochastic processes

来源：评论

学校读者我要写书评

暂无评论

Multiple-Hypothesis Vision-Based Landing Autonomy

引用

JOURNAL OF AEROSPACE INFORMATION SYSTEMS 2020年第9期17卷 528-545页

作者： Nakamura, Takuma Johnson, Eric N. Georgia Inst Technol Sch Aerosp Engn Atlanta GA 30332 USA Penn State Univ Aerosp Engn University Pk PA 16802 USA

This paper presents a novel state estimation system for unmanned aerial vehicle landing. A novel vision algorithm that detects a portion of the marker is developed, and this algorithm extends the detectable range of the vision system for any known marker. A vision-aided navigation algorithm is derived within extended Kalman particle filter and Rao-Blackwellized particle filter frameworks in addition to a standard extended Kalman filter framework. These multihypothesis approaches not only deal well with a highly nonlinear and non-Gaussian distribution of the measurement errors of vision but also result in numerically stable filters. The computational costs are reduced compared to a naive implementation of particle filter, and these algorithms run in real time. This system is validated through numerical simulation, image-in-the-loop simulation, and flight tests.

关键词： Vision Based Landing Unscented Kalman Filter Flight Testing Autonomous Vision Based Landing Numerical Simulation navigation algorithm Number of Particles GPS Simultaneous Localization and Mapping Monte Carlo Simulation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：