检索结果-内蒙古大学图书馆

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Misra, Gaurav Bai, Xiaoli Rutgers State Univ Dept Mech & Aerosp Engn Piscataway NJ 08854 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

In this paper, a convex optimization based approach is proposed for solving the relative spacecraft guidance problem with non-convex obstacle avoidance constraints akin to sequential convex programming approaches proposed in literature, which require solving a sequence of simpler convex programs. However, contrary to existing approaches, the method proposed in this paper ensures that the iterates remain feasible as long as the first iterate is feasible and achieves monotonic convergence of the objective function. Significantly, the proposed methodology leads to anytime solutions, i.e., the computation can be aborted whenever needed and still return a quality solution, which is highly desirable for real-time operations due to potential unexpected situations and limited computation resources. However, most existing methods only guarantee the correctness of the solution when they converge, whereas preconvergence solution obtained can be useless or even dangerous when applied. The underlying methodology assumes linear dynamics with polynomial path constraints and relies on the convex-concave procedure and sum-of-squares programming to obtain tractable inner convex approximations. To validate the efficacy of the proposed method, a relative spacecraft fuel optimal guidance problem under Clohessy-Hill-Wiltshire (CHW) dynamics is studied under plume impingement, keep-out zones, and obstacle avoidance constraints.

关键词： nonlinear programming Spacecraft Trajectory Optimization Model Predictive Control Optimal Control Algorithms Convergence Sequential Quadratic programming Pseudo Spectral Method Boundary Value Problems Guidance Laws Rockets

来源：评论

学校读者我要写书评

暂无评论

Quadrupedal Robotic Walking on Sloped Terrains via Exact Decomposition into Coupled Bipedal Robots

Quadrupedal Robotic Walking on Sloped Terrains via Exact Dec...

引用

IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

作者： Ma, Wen-Loong Csomay-Shanklin, Noel Ames, Aaron D. CALTECH Dept Mech Engn Pasadena CA 91125 USA CALTECH Dept Control Dynam Syst Pasadena CA 91125 USA

ISBN: (纸本)9781728162126

Can we design motion primitives for complex legged systems uniformly for different terrain types without neglecting modeling details? This paper presents a method for rapidly generating quadrupedal locomotion on sloped terrains-from modeling to gait generation, to hardware demonstration. At the core of this approach is the observation that a quadrupedal robot can be exactly decomposed into coupled bipedal robots. Formally, this is represented through the framework of coupled control systems, wherein isolated subsystems interact through coupling constraints. We demonstrate this concept in the context of quadrupeds and use it to reduce the gait planning problem for uneven terrains to bipedal walking generation via hybrid zero dynamics. This reduction method allows for the formulation of a nonlinear optimization problem that leverages low-dimensional bipedal representations to generate dynamic walking gaits on slopes for the full-order quadrupedal robot dynamics. The result is the ability to rapidly generate quadrupedal walking gaits on a variety of slopes. We demonstrate these walking behaviors on the Vision 60 quadrupedal robot;in simulation, via walking on a range of sloped terrains of 13 degrees, 15 degrees, 20 degrees, 25 degrees, and, experimentally, through the successful locomotion of 13 degrees and 20 degrees similar to 25 degrees sloped outdoor grasslands.

关键词： nonlinear programming

来源：评论

学校读者我要写书评

暂无评论

nonlinear OPTIMAL CONTROL OF A DEEP BOREHOLE TRAJECTORY DESIGN 39

NONLINEAR OPTIMAL CONTROL OF A DEEP BOREHOLE TRAJECTORY DESI...

引用

ASME 39th International Conference on Ocean, Offshore and Arctic Engineering (OMAE)

作者： Gulyayev, Valery Glazunov, Sergii Andrusenko, Olena Natl Transport Univ Kiev Ukraine

ISBN: (纸本)9780791884317

In modern oil/gas producing industry, vertical, 2D and 3D directed, and multilateral (branched) boreholes are drilled. Their trajectories are designed depending on the petroleum deposit depth and structure, properties of mining rocks, their hardness, heterogeneity, fracturing anisotropy, permeability, and so on. Therefore, the borehole cost and its productivity are determined by the length, smoothness, and configuration of its trajectory. To enhance efficiency of a borehole and to reduce cost of its drivage, to enlarge rate and volume of the reservoir depletion, it is proposed to use methods of optimal control for the best tracking of its trajectory. Through application of the differential geometry correlations, the mathematic model of the borehole outline in the form of nonlinear ordinary differential equations system is elaborated. Different objective functions, representing total integral curvature of the borehole axis line, its length, and cost of its drivage, are selected;additional constraints, separating allowed and forbidden zones of passing, are chosen. The functions of the trajectory curvature and torsion are used as controlling variables. The continuous correlations of the model are discretized and, further, the techniques of nonlinear programming and optimal control are employed. On the basis of the method of objective function gradient (antigradient) projection on the linearized constraint planes, the step-by-step algorithm of approaching to the optimal trajectory is elaborated. To correct the spoilt constraints, at every step of calculations, the Newton method is used. The elaborated approach is applied to optimization of deep curvilinear borehole outlines. The results of numerical analysis are discussed. It is shown that smoothing the hole trajectory permits also to diminish the contact and frictional interaction between the drill string and bore-hole wall and, by this, to decrease the resistance forces acting on the string during tripping in/out oper

关键词： String Permeability Drill strings Numerical analysis Trajectories (Physics) nonlinear programming Fracture (Process) Reservoirs Differential equations Algorithms Geometry Design Optimal control Wear Mining Probability Rocks Optimization Newton's method Torsion Petroleum Anisotropy

来源：评论

学校读者我要写书评

暂无评论

On Neural Network Training from Noisy Data using a Novel Filtering Framework

On Neural Network Training from Noisy Data using a Novel Fil...

引用

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Deshpande, Vedang Das, Niladri Tadiparthi, Vaishnav Bhattacharyya, Raktim Texas A&M Univ Dept Aerosp Engn College Stn TX 77843 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

We discuss a novel method to train a neural network from noisy data, using Optimal Transport based filtering. We show a comparative study of this methodology with three other filters: the Extended Kalman filter, the Ensemble Kalman filter, and the Unscented Kalman filter, that can also be used for the purpose of training a neural network. We empirically establish that Optimal Transport based filter performs better than the other three filters with respect to root mean square error measure, for non-Gaussian noise in the output. We demonstrate the efficacy of utilizing the Optimal Transport based filtering for neural network training in the context of predicting Mackey-Glass chaotic time series data.

关键词： Neural Networks Unscented Kalman Filter Stochastic Gradient Descent Probability Density Functions Fluid Structure Interaction Space Situational Awareness Aerospace Engineering nonlinear programming nonlinear Systems Taylor Series

来源：评论

学校读者我要写书评

暂无评论

Research on the Impact of Open Residential Roads on Traffic Capability 5

Research on the Impact of Open Residential Roads on Traffic ...

引用

IEEE 5th International Conference on Computer and Communication Systems (ICCCS)

作者： Qian, Qi-pei Bao, Kai-xuan Zhao, Kai Lu, Yin Nanjing Univ Posts & Telecommun Bell Honors Sch Nanjing Peoples R China Nanjing Univ Posts & Telecommun Jiangsu Key Lab Wireless Commun Nanjing Peoples R China

ISBN: (纸本)9781728161365

Predicting the impact of open residential roads will have significance not only for transportation planning and economic development, but also for the enhancement of human society. Aiming at the problem of different road and community structure, this paper considers the road length, road speed limit, traffic volume, traffic lights, and other factors to improve the traffic capability. Then uses nonlinear programming to obtain the optimal solution based on BPR road impedance model. Finally, based on different residential road structures and traffic pressure, the enhancement of open residential roads is compared to find out which road structure is optimal for opening.

关键词： component open residential roads BPR road impedance model nonlinear programming

来源：评论

学校读者我要写书评

暂无评论

A Real-Time Approach to Minimum-Energy Reorientation of an Asymmetric Rigid Body Spacecraft

A Real-Time Approach to Minimum-Energy Reorientation of an A...

引用

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： McDonald, Spencer T. Grizzel, Timothy L. Wang, Zhenbo Univ Tennessee Dept Mech Aerosp & Biomed Engn Knoxville TN 37996 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

The minimum-energy fixed-time rest-to-rest reorientation of an asymmetric rigid-body spacecraft is investigated. The problem is first formulated as a non-convex optimal control problem using a quaternion based dynamic model. Past attempts at solving this problem either sacrifice fidelity to solve analytically or require computationally intensive nonlinear programming (NLP) solvers to tackle the original problem. However, through discretization and constraint implementation, the original optimal control problem is transformed into a sequential convex programming (SCP) problem. Additionally, a simple line search method is introduced to aid in the convergent process of the SCP method. Through numerical demonstrations, the SCP approach has been shown to converge to the minimum-energy optimal solution, even with trivial initial trajectories. The solutions are validated through a comparison with an NLP-based solver, GPOPS. Additionally, line search (LS) has been shown to aid convergence of SCP by decreasing the number of iterations by a significant amount. This introduces a novel approach to solve the minimum-energy fixed-time rest-to-rest reorientation in real time.

关键词： Rigid Spacecraft nonlinear programming Trajectory Optimization Quaternions nonlinear Dynamics Quadratic programming Predictor Corrector Method Euler Angles Control Optimization Linear Interpolation

来源：评论

学校读者我要写书评

暂无评论

Packing Irregular Polygons using Quasi Phi-functions 10

Packing Irregular Polygons using Quasi Phi-functions

引用

10th International Conference on Advanced Computer Information Technologies (ACIT)

作者： Pankratov, Alexandr Romanova, Tatiana Shekhovtsov, Sergiy Grebennik, Igor Pankratova, Julia Kharkiv Natl Univ Radioelect Dept Syst Engn Natl Acad Sci Ukraine Dept Math Modelind & Optimal DesignInst Mech Eng Kharkiv Ukraine Kharkiv Natl Univ Radioelect Dept Syst Engn Kharkiv Natl Univ Internal Affairs Dept Informat Technol Kharkiv Ukraine Kharkiv Natl Univ Radioelect Dept Syst Engn Kharkiv Ukraine

ISBN: (纸本)9781728167602

Packing simply connected irregular polygons in an optimized convex container is considered. Each object allows free continuous moving. We use quasi phi-functions for describing non-overlapping relations of irregular polygons. An exact mathematical model of the packing problem is provided. The fast algorithm to search for feasible arrangements of irregular polygons is proposed. The optimization procedure to find good local extrema is presented. Computational results illustrated with new benchmark instances are given.

关键词： packing non-convex polygons convex container quasi phi-function nonlinear programming

来源：评论

学校读者我要写书评

暂无评论

Direct Methods Comparison for the Active Target Defense Scenario

Direct Methods Comparison for the Active Target Defense Scen...

引用

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Weintraub, Isaac E. Cobb, Richard Baker, William Pachter, Meir US Air Force Res Lab Wright Patterson AFB OH 45433 USA US Air Force Res Lab Dept Aerosp Engn Wright Patterson AFB OH 45433 USA US Air Force Res Lab Dept Mathemat Wright Patterson AFB OH 45433 USA US Air Force Res Lab Dept Elect Engn Wright Patterson AFB OH 45433 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

The goal of optimal control is to obtain an admissible function which minimizes an objective functional subject to specified constraints and boundary conditions. Four popular methods of computing the optimal control directly are the Single Shooting Method, Multiple Shootings Method, Even Collocation Method, and Pseudospectral Method. In this paper, the four direct methods of computing the optimal control for the Active Target Defense Scenario are presented and compared. The Active Target Defense Scenario is a three-agent engagement where an evading agent tries to escape a pursuing agent with the assistance of a defending agent. The goal of the Evader is to maneuver in such a way as to assist the Defender in capturing the Pursuer while maximizing his range from the Pursuer. This work begins by describing each direct method and summarizing advantages and disadvantages of each. Next, each method is used to solve the optimal control for the Active Target Defense Scenario;results are presented and a comparison of the performance of each method is made. Finally, concluding remarks describing the results, performance, and real-time implementation are presented.

关键词： Optimal Control Theory Gaussian Quadrature Pseudospectral Methods Parallel Computing Techniques nonlinear programming Sequential Quadratic programming Heading Angle Proportional Navigation Runge Kutta Methods MATLAB

来源：评论

学校读者我要写书评

暂无评论

Non-intrusive Time-POD for Optimal Control of a Fixed-Bed Reactor for CO 2 Methanation

引用

IFAC-PapersOnLine 2021年第3期54卷 122-127页

作者： Jens Bremer Jan Heiland Peter Benner Kai Sundmacher Max Planck Institute Magdeburg Dpt. Process Systems Engineering Sandtorstraße 2 39106 Magdeburg Germany and Otto von Guericke University Magdeburg Chair for Process Systems Engineering Universitätsplatz 2 39106 Magdeburg (Sundmacher) Max Planck Institute Magdeburg Dpt. Computational Methods in Systems and Control Theory and Otto von Guericke University Magdeburg Fakultät für Mathematik

The optimization of a controlled process in a simulation without access to the model itself is a common scenario and very relevant to many chemical engineering applications. A general approach is to apply a black-box optimization algorithm to a parameterized control scheme. The success then depends on the quality of the parametrization that should be low-dimensional though rich enough to express the salient features. This work proposes using solution snapshots to extract dominant modes of the temporal dynamics of a process and use them for low-dimensional parametrizations of control functions. The approach is called proper orthogonal decomposition in time (time-POD). We provide theoretical reasoning and illustrate the performance for the optimal control of a methanation reactor.

关键词： Optimal control Model order reduction Proper orthogonal decomposition Fixed-bed reactor Carbon dioxide methanation nonlinear programming Black-box model

来源：评论

学校读者我要写书评

暂无评论

Scheduling bus holding times in time horizons considering transfer synchronization and service regularity 23

Scheduling bus holding times in time horizons considering tr...

引用

23rd IEEE International Conference on Intelligent Transportation Systems (ITSC)

作者： Voorhorst, Jesse Gkiotsalitis, Konstantinos Univ Twente Dept Civil Engn Enschede AE Netherlands

ISBN: (纸本)9781728141497

Transfers between public transport modes hinder the traveling by public transport due to the unreliability and long waiting times. Nonetheless, public transport operators are mainly interested in maintaining the regularity of different lines without accounting for the transfer waiting times. This work focuses on the application of bus holding to reduce the transfer waiting times, in-vehicle waiting times, and the deviation from the target headways. The determination of optimal holding times is performed in time horizons (e.g., hourly time periods) where past events are fixed, while future events are considered in the optimization process. This study models the bus holding problem which considers transfer synchronization as a nonlinear convex program (NLP) that can be solved by off-the-shelf solvers. Our approach is tested against state-of-the-art bus holding methods in a case study on the bus network of Almere (Netherlands) demonstrating a significant reduction in the transferring waiting times.

关键词： scheduling holding times transfer synchronization bus regularity nonlinear programming

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：