检索结果-内蒙古大学图书馆

closed-loop system identification with Genetic Algorithms

JOURNAL OF AEROSPACE COMPUTING INFORMATION AND COMMUNICATION 2008年第6期5卷 161-173页

作者： Whorton, Mark S. NASA George C Marshall Space Flight Ctr Huntsville AL 35812 USA

High-performance control design for a flexible space structure is challenging as high-fidelity plant models are difficult to obtain a priori. Uncertainty in the control design models typically require a very robust, low-performance control design, which must be tuned on-orbit to achieve the required performance. closed-loop system identification is often required to obtain a multivariable open-loop plant model based on closed-loop response data. To provide an accurate initial plant model to guarantee convergence for standard local optimization methods, this paper presents a global parameter optimization method using genetic algorithms. A minimal representation of the state space dynamics is used to mitigate the nonuniqueness and overparameterization of general state space realizations. This control-relevant system identification procedure stresses the joint nature of the system identification and control design problem by seeking to obtain a model that minimizes the difference between the predicted and actual closed-loop performance.

关键词： Genetic Algorithm closed loop system identification Space Structures Stiffness Matrices Linear Quadratic Gaussian Model Order Reduction Damping Ratio Spacecraft Instruments Describing Function Flexible Structures

来源：评论

学校读者我要写书评

暂无评论

Real-Time closed-loop system identification of a Quadcopter

引用

JOURNAL OF AIRCRAFT 2019年第1期56卷 324-335页

作者： Alabsi, Mohammed I. Fields, Travis D. Univ Missouri Civil & Mech Engn 5110 Rockhill Rd Kansas City MO 64110 USA

Real-time estimation of dynamic model parameters for an unmanned aircraft can provide valuable information about the dynamics of the vehicle. However, the aircraft model estimation performance can be severely degraded with an active control system and highly collinear model terms such as those found on a quadrotor unmanned aircraft. Model parameters were estimated based on dynamic flight data of a quadcopter aircraft. system identification maneuvers were generated using varying-amplitude orthogonal multisine input signals applied on a quadcopter with nominal hardware conditions and with a damaged propeller. Recursive Fourier transform regression was applied to dynamic data to estimate parameters of two input model forms: independent and delta input. Prediction capability of the identified models was assessed using data of nearly the same flight conditions. Results indicated that, as the amplitude of the input multisine increased, the identifiability of control effectiveness improved, and prediction error decreased. Overall, a well-designed multi-input multisine input design and Fourier transform regression applied together provided efficient and accurate real-time parameter estimation that effectively overcame challenges imposed by a system subjected to closed-loop control with collinear model terms.

关键词： closed loop system identification Quadcopter Propellers Flight Data Unmanned Aircraft Control Surfaces Flight Testing Pulse Width Modulation Extended Kalman Filter Multirotor

来源：评论

学校读者我要写书评

暂无评论

The practical analysis for closed-loop system identification

引用

COGENT ENGINEERING 2020年第1期7卷 Article: 1796895页

作者： Jianhong, Wang Ramirez-Mendoza, Ricardo A. Jiangxi Univ Sci & Technol Sch Elect Engn & Automat Ganzhou Peoples R China Tecnol Monterrey Sch Sci & Engn Monterrey Mexico

As the existed theories for closed-loop system identification are very mature, and in this short note, one common closed-loopclosed-loop system is considered, then the classical prediction error identification is reviewed for closed-loop system identification. Based on above-existed results on closed-loop system identification, here we continue to do some research on closed-loop system identification from the practical perspective. It means all mathematical derivations and results, proposed here are more general than those existed results from references, and all results are more suited for the practical application. More specifically, the cost function, used to minimize with respect to the unknown parameter, is derived again to its more simplified form. The identification for the unknown plant is obtained again from the point of its usual spectral analysis estimation. After choosing one suited coefficient matrix into the explicit expression about the cost function, one optimal feedback controller or optimal control input is derived to be global minimum. Our derived spectral analysis estimation, simplified cost function, and optimal feedback controller are beneficial for embodying the relations with all input- output signal and other variables, such as the true plant, parameter estimator, spectral analysis estimation etc. Finally, one simulation example has been performed to demonstrate the effectiveness of the theories proposed in this paper.

关键词： closed loop system identification practical analysis optimal feedback controller

来源：评论

学校读者我要写书评

暂无评论

Assessment of Multi-Joint Coordination and Adaptation in Standing Balance: A Novel Device and system identification Technique

引用

IEEE TRANSACTIONS ON NEURAL systemS AND REHABILITATION ENGINEERING 2015年第6期23卷 973-982页

作者： Engelhart, Denise Schouten, Alfred C. Aarts, Ronald G. K. M. van der Kooij, Herman Univ Twente MIRA Inst Biomed Technol & Tech Med Dept Biomech Engn NL-7500 AE Enschede Netherlands Delft Univ Technol Dept Biomech Engn NL-2628 CD Delft Netherlands Univ Twente Dept Mech Automat NL-7500 AE Enschede Netherlands

The ankles and hips play an important role in maintaining standing balance and the coordination between joints adapts with task and conditions, like the disturbance magnitude and type, and changes with age. Assessment of multi-joint coordination requires the application of multiple continuous and independent disturbances and closed loop system identification techniques (CLSIT). This paper presents a novel device, the double inverted pendulum perturbator (DIPP), which can apply disturbing forces at the hip level and between the shoulder blades. In addition to the disturbances, the device can provide force fields to study adaptation of multi-joint coordination. The performance of the DIPP and a novel CLSIT was assessed by identifying a system with known mechanical properties and model simulations. A double inverted pendulum was successfully identified, while force fields were able to keep the pendulum upright. The estimated dynamics were similar as the theoretical derived dynamics. The DIPP has a sufficient bandwidth of 7 Hz to identify multi-joint coordination dynamics. An experiment with human subjects where a stabilizing force field was rendered at the hip (1500 N/m), showed that subjects adapt by lowering their control actions around the ankles. The stiffness from upper and lower segment motion to ankle torque dropped with 30% and 48%, respectively. Our methods allow to study (pathological) changes in multi-joint coordination as well as adaptive capacity to maintain standing balance.

关键词： Adaptation closed loop system identification multi-joint coordination standing balance control

来源：评论

学校读者我要写书评

暂无评论

SURVEY OF EXPERIMENTS AND EXPERIMENTAL FACILITIES FOR CONTROL OF FLEXIBLE STRUCTURES

引用

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1992年第4期15卷 801-816页

作者： SPARKS, DW JUANG, JN NASA Langley Research Center Hampton Virginia 23665

This paper presents a survey of ground experiments primarily conducted in the United States and U.S. facilities dedicated to the study of active control of flexible structures. The facilities are briefly described in terms of capability, configuration, size, and instruments. Topics on the experiments include vibration suppression, slewing control, and system identification. The experiments are listed in tables containing the experiment's name, the responsible organization, a brief description of the test article configuration, and the actuator/sensor devices used in the experiment. Selected experiments will be further discussed to help illustrate the control problems. Some of the test facilities dedicated to ground testing of large space structures are discussed in more detail, to give the reader a better appreciation of ground-testing work. Several research issues are mentioned, including real-time computer systems, test article suspension, and new actuator/sensor technology development.

关键词： Flexible Structures Piezoelectric Actuators Proximity Sensors closed loop system identification Large Space Structures Vibration Suppression Computer systems Marshall Space Flight Center Spacecraft Control American Astronautical Society

来源：评论

学校读者我要写书评

暂无评论

identification for control of multivariable systems: Controller validation and experiment design via LMIs

引用

AUTOMATICA 2008年第12期44卷 3070-3078页

作者： Barenthin, Marta Bombois, Xavier Hjalmarsson, Hakan Scorletti, Gerard KTH Sch Elect Engn S-10044 Stockholm Sweden Delft Ctr Syst & Control NL-2628 CD Delft Netherlands Ecole Cent Lyon Lab Ampere F-69134 Ecully France

This paper presents a new controller validation method for linear multivariable time-invariant models. Classical prediction error system identification methods deliver uncertainty regions which are nonstandard in the robust control literature. Our controller validation criterion computes an upper bound for the worst case performance, measured in terms of the H(infinity)-norm of a weighted closed loop transfer matrix, achieved by a given controller over all plants in such uncertainty sets. This upper bound on the worst case performance is computed via an LMI-based optimization problem and is deduced via the separation of graph framework. Our main technical contribution is to derive, within that framework, a very general parametrization for the set of multipliers corresponding to the nonstandard uncertainty regions resulting from PE identification of MIMO systems. The proposed approach also allows for iterative experiment design. The results of this paper are asymptotic in the data length and it is assumed that the model structure is flexible enough to capture the true system. (C) 2008 Elsevier Ltd. All rights reserved.

关键词： identification for robust control Experiment design closed loop system identification Controller validation Multivariable plants Linear multivariable feedback LMI optimization

来源：评论

学校读者我要写书评

暂无评论

Aeroservoelastic Test of the Subsonic Ultra-Green Aircraft Research Truss-Braced Wing Model

引用

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2016年第8期39卷 1820-1833页

作者： Scott, Robert C. Bartels, Robert E. Funk, Christie J. Allen, Timothy J. Sexton, Bradley W. Dykman, John R. Coulson, David A. NASA Langley Res Ctr MS 340 Hampton VA 23681 USA Boeing Res & Technol Loads & Aeroelast 14900 Bolsa Chica RdMS H017-D601 Huntington Beach CA 92647 USA Boeing Res & Technol Navigat & Control 325 James S McDonnell BlvdMS S306-4030 Huntington Beach CA 92647 USA Boeing Res & Technol 14900 Bolsa Chica RdMS H017-D601 St Louis MO 63042 USA Analyt Serv Mat Inc NASA Langley Res Ctr MS 340 Hampton VA 23681 USA

The Subsonic Ultra Green Aircraft Research Truss-Braced Wing aeroservoelastic wind-tunnel test was conducted in the NASA Langley Transonic Dynamics Tunnel. The primary goals of the test were to identify the open-loop flutter boundary and then demonstrate flutter suppression. A secondary goal was to demonstrate gust load alleviation. Open-loop flutter and limit cycle oscillation onset boundaries were identified for a range of Mach numbers and various angles of attack. Two sets of control laws were designed for the model, and both sets of control laws were successful in suppressing flutter. Control laws optimized for gust load alleviation were not designed;however, the flutter suppression control laws were assessed using the Transonic Dynamics Tunnnel airstream oscillation system. This paper describes the experimental apparatus, procedures, and results of the truss-braced wing wind-tunnel model test. Acquired system identification data used to generate aeroservoelastic models are also discussed.

关键词： Aircrafts Trusses closed loop system identification Aerodynamic Efficiency Wind Tunnel Models Aerodynamics Langley Transonic Dynamics Tunnel Finite Element Modeling Control Surfaces Data Acquisition system

来源：评论

学校读者我要写书评

暂无评论

Data-Driven Retrospective Cost Adaptive Control for Flight Control Applications

引用

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2021年第10期44卷 1732-1758页

作者： Ul Islam, Syed Aseem Nguyen, Tam W. Kolmanovsky, Ilya, V Bernstein, Dennis S. Univ Michigan Aerosp Engn 1320 Beal Ave Ann Arbor MI 48109 USA

Unlike fixed-gain robust control, which trades off performance with modeling uncertainty, direct adaptive control uses partial modeling information for online tuning. The present paper combines retrospective cost adaptive control (RCAC), a direct adaptive control technique for sampled-data systems, with online system identification based on recursive least squares (RLS) with variable-rate forgetting (VRF). The combination of RCAC and RLS-VRF constitutes data-driven RCAC (DDRCAC), where the online system identification is used to construct the target model, which defines the retrospective performance variable. This paper investigates the ability of RLS-VRF to provide the modeling information needed for the target model, especially non-minimum-phase (NMP) zeros. DDRCAC is applied to single-input, single-output and multiple-input, multiple-output numerical examples with unknown NMP zeros, as well as several flight control problems, namely, unknown transition from minimum phase to NMP lateral dynamics, flexible modes, flutter, and nonlinear planar missile dynamics.

关键词： Retrospective Cost Flight Control closed loop system identification Benchmark Active Control Technology Sampled Data systems Missile Dynamics Linear Quadratic Gaussian Gaussian White Noise Elevator Deflection Aerodynamic Coefficients

来源：评论

学校读者我要写书评

暂无评论

Time-varying Observer/Controller identification Algorithm: Applications in Guidance, Navigation and Control

Time-varying Observer/Controller Identification Algorithm: A...

引用

AIAA SciTech Forum

作者： Gueho, Damien GeminusAI Cambridge MA 02114 USA

ISBN: (数字)9781624107115

ISBN: (纸本)9781624107115

Accurate and distinct modeling of process and controller dynamics arises in cases where a system may be operating in closed-loop and only closed-loop data are available for identification or if an open-loop model of the system is required to be identified from closed-loop data for the purpose of structural analysis or controller re-design. This paper introduces a method for identification of a closed-loop linear time-varying (LTV) system and observer/controller dynamics from experimental data only. Generalized observer/controller Markov parameters are computed from the given set of excitation signal, feedback control signal, and closed-loop response data. The system, observer gain, and controller gain Markov parameters are recovered from the identified observer/controller Markov parameters and a state-space model of the system as well as the corresponding observer and controller gains are identified using a statespace identification method such as the time-varying eigensystem realization algorithm. In the absence of noise, the open-loop system and the full-state feedback gain can be identified exactly. Modal parameters including frequencies, dampings, mode shapes at the sensor locations are then recovered from the open-loop system matrices. Two numerical examples are considered to demonstrate the applicability of this framework for guidance, navigation and control applications.

关键词： Eigensystem Realization Algorithm closed loop system identification Feedback Control system Structural Analysis Sensors Optimal Control Problem Aerospace Engineering Gaussian White Noise Control system Design Flight Control

来源：评论

学校读者我要写书评

暂无评论

Predictive Cost Adaptive Control of the BACT Flutter Model

Predictive Cost Adaptive Control of the BACT Flutter Model

引用

AIAA SciTech Forum

作者： Richards, Riley J. Islam, S. A. U. Bernstein, Dennis S. Univ Michigan Dept Aerosp Engn Ann Arbor MI 48109 USA

ISBN: (数字)9781624107115

ISBN: (纸本)9781624107115

This paper provides a numerical investigation of the performance of predictive cost adaptive control (PCAC) of the NASA BACT flutter model. PCAC is an indirect adaptive control extension of model predictive control that includes online closed-loop system identification. system identification is based on recursive least squares with variable-rate forgetting based on the F-test. PCAC is applied to the BACT flutter model, and the ability of PCAC to extend the flutter boundary using minimal prior modeling of the aeroelastic dynamics is investigated through detailed and systematic numerical simulations.

关键词： Benchmark Active Control Technology closed loop system identification NASA Numerical Simulation Airspeed Aerodynamic Damping Accelerometer Angle of Attack Inertial Coupling Turbulence Models

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：