检索结果-内蒙古大学图书馆

adaptive Attitude-Tracking control of Spacecraft with Uncertain Time-Varying Inertia Parameters

JOURNAL OF GUIDANCE control AND DYNAMICS 2015年第1期38卷 41-52页

作者： Thakur, Divya Srikant, Sukumar Akella, Maruthi R. Univ Texas Austin Dept Aerosp Engn & Engn Mech Austin TX 78712 USA Indian Inst Technol Mumbai 400076 Maharashtra India

Although adaptive control schemes for spacecraft attitude tracking are abundant in controls literature, very few are designed to guarantee consistent performance for a spacecraft with both rigid and nonrigid (time-varying) inertia components. Because inertia matrix changes are a common occurrence due to phenomena like fuel depletion or mass displacement in a deployable spacecraft, an adaptive control algorithm that takes explicit account of such information is of significant interest. In this paper, a novel adaptive attitude control scheme is presented for a spacecraft with inertia matrix parameters that have both unknown rigid components and only partially determined variable components. The proposed controller directly compensates for inertia variations that occur as either pure functions of the control input, or as functions of time. For the particular case of an input-dependent inertia matrix, a bounded control solution is ensured by placing some mild restrictions on the initial conditions and by employing a smooth projection scheme that confines the parameter estimates to a well-dMefined convex set. Detailed derivations of the control law are provided, along with a thorough analysis for the associated stability and error convergence properties. In addition, numerical simulations are presented to highlight the performance benefits when compared with an adaptive control scheme that does not account for inertia variations.

关键词： Rigid Spacecraft Attitude Tracking adaptive control algorithm Numerical Simulation Attitude Dynamics Spacecraft Attitude Quaternions Propellant Full State Feedback Mathematical Models

来源：评论

学校读者我要写书评

暂无评论

Design of an adaptive feedforward/feedback combined control for piezoelectric actuated micro positioning stage

引用

PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY 2022年 78卷 199-205页

作者： Shi, Beichao Shi, Rui Wang, Fujun Tianjin Univ Sch Mech Engn Key Lab Mech Theory & Equipment Design Minist Educ Tianjin 300354 Peoples R China

This paper proposes a novel feedforward/feedback combined control applied to a piezoelectric (PZT) actuated micro positioning stage. Based on the rate-dependent P-I inverse hysteresis model, a feedforward controller is built to compensate the hysteresis characteristics of the piezoelectric actuators, and the relevant parameters of the model are obtained through system identification. An adaptive control algorithm is adopted in feedback controller to reduce the influence of external disturbance. By introducing error-related forgetting factors to adjust the weight of old data and new data in real time, the robustness and accuracy of the control system are improved. The simulations are carried out to estimate the performance of the time-varying forgetting factors based adaptive algorithm. Finally, experimental tests are conducted to investigate the performance of the pro-posed feedforward/feedback combined control. The experimental results indicates that the settling time is 53 ms corresponding to the square wave signal and the maximum tracking error of a sine trajectory with the frequency of 20 Hz is 1.63 mu m.

关键词： feedback combined control P -I inverse Hysteresis model adaptive control algorithm Error-related forgetting factors Micro positioning stage

来源：评论

学校读者我要写书评

暂无评论

Active Suspension Method and Active Vibration control of a Hoop Truss Structure

引用

AIAA JOURNAL 2018年第4期56卷 1689-1695页

作者： Ma, Guoliang Gao, Bo Xu, Minglong Feng, Bo Xi An Jiao Tong Univ State Key Lab Strength & Vibrat Mech Struct Sch Aerosp Xian 710049 Shaanxi Peoples R China

The hoop truss structure is an indispensable structure of communication satellite antennas. Because the hoop truss structure can deform and seriously vibrate, a ground test is essential before application. This paper first introduces an active suspension method of lifting the structure. Voice coil actuators are used to output an Ampere force that balances the gravity of the structure. Under the condition that the two damped frequencies of the suspension structure and no-suspension structure are equal to each other, the active suspension method is available on the ground. Active vibration control is then investigated to suppress vibration responses. According to a proportional-plus-derivative algorithm and fuzzy algorithm, the control force is calculated and generated by another voice coil actuator. Finally, excitation and closed-loop control experiments are conducted to suppress the nod mode vibration under transient excitation and steady-state excitation. Experimental results show that the actuator effectively suppresses the nod mode vibration of the hoop truss structure.

关键词： Active Vibration control adaptive Truss Piezoelectric Stack Actuator adaptive control algorithm Communications Satellite Resonance Frequencies Fuzzy control Signal Generator Satellites Flexible Structures

来源：评论

学校读者我要写书评

暂无评论

Adaptation of centers of approximation for nonlinear tracking control

引用

JOURNAL OF GUIDANCE control AND DYNAMICS 1996年第2期19卷 363-369页

作者： Kurdila, AJ Petersen, JL Texas A&M University College Station Texas 77843-3141

Sufficient conditions for the asymptotic stability and exponential convergence of tracking control for nonlinear systems have proliferated in recent research, Various theories for stability have been related to, and rely upon, the functional form of the governing nonlinear equations, the linearizability of the governing equations by canonical (Lie) transformations, the linear appearance of adaptive parameters, and the richness of the input excitation. Previously, sufficient conditions have been derived for a class of Hamiltonian adaptive tracking control problems using radial basis function approximants. We demonstrate that a crucial element determining the performance of this class of tracking control methodologies is the location of the centers of approximation in the radial basis approximant/network. A learning vector quantization algorithm is employed to simultaneously adapt both the centers of approximation and the feedback gains. The simultaneous adaptation of both approximant centers in configuration space and feedback gains can demonstrate remarkable improvements in convergence rate, as compared to adaptation of feedback gains alone.

关键词： adaptive control algorithm Nonlinear Equation Radial Basis Function Network Feedback control Shape Functions NASA Langley Large Space Structures Four Degree of Freedom Numerical Stability Nonlinear control

来源：评论

学校读者我要写书评

暂无评论

Time-averaged gradient control of thermoacoustic instabilities

引用

JOURNAL OF PROPULSION AND POWER 2003年第5期19卷 830-836页

作者： Vaudrey, MA Baumann, WT Saunders, WR Adapt Technol Inc Blacksburg VA 24060 USA Virginia Polytech Inst & State Univ Dept Elect & Comp Engn Blacksburg VA 24060 USA Virginia Polytech Inst & State Univ Dept Mech Engn Blacksburg VA 24060 USA

Active control of thermoacoustic instabilities has been an important topic of research for many years. In particular, adaptive-control approaches are continually investigated because of their potential ability to adjust to changing and unknown operating conditions. Most adaptive controllers are model based and require accurate knowledge of the plant to which they are applied;this is currently an extremely challenging solution for the limit-cycling combustion plant. A more versatile controller approach, based on a gradient descent algorithm, is presented here. The time-averaged gradient controller can automatically adapt to changing plants and can assume a variety of different controller architectures and actuator styles, without the need for any explicit knowledge of the plant dynamics. We present the controller in a variety of forms and provide simulation and experimental results illustrating its effectiveness in stabilizing an unstable Rijke tube combustor and a 50-kW kerosene-fueled lean direct-injection combustor.

关键词： Combustor Design Actuators adaptive control algorithm Kerosene Feedback control Newton's Method algorithm Performance Combustion Instability Method of Steepest Descent Linear Quadratic Gaussian

来源：评论

学校读者我要写书评

暂无评论

Robust adaptive Model Tracking for Distributed Parameter control of Linear Infinite-dimensional Systems in Hilbert Space

引用

IEEE/CAA Journal of Automatica Sinica 2014年第3期1卷 294-301页

作者： Mark J.Balas Susan A.Frost the Embry-Riddle Aeronautical University the NASA Ames Research Center

This paper is focused on adaptively controlling a linear infinite-dimensional system to track a finite-dimensional reference *** a linear continuous-time infinite-dimensional plant on a Hilbert space with disturbances of known waveform but unknown amplitude and phase,we show that there exists a stabilizing direct model reference adaptive control law with the properties of certain disturbance rejection and *** plant is described by a closed,densely defined linear operator that generates a continuous semigroup of bounded operators on the Hilbert space of *** central result will show that all errors will converge to a prescribed neighborhood of zero in an infinitedimensional Hilbert *** result will not require the use of the standard Barbalat’s lemma which requires certain signals to be uniformly *** result is used to determine conditions under which a linear infinite-dimensional system can be directly adaptively controlled to follow a reference *** particular,we examine conditions for a set of ideal trajectories to exist for the tracking *** results are applied to adaptive control of general linear diffusion systems described by self-adjoint operators with compact resolvent.

关键词： Adaptation models adaptive control Hilbert space Learning (artificial intelligence) Robustness Trajectory adaptive control algorithm adaptive theory distributed parameter system Distributed parameter systems Hilbert space trajectory Adaptation models reference model adaptive control Robustness Computer algorithms

来源：评论

学校读者我要写书评

暂无评论

EXPERIMENTS IN MULTIVARIABLE adaptive-control OF A LARGE FLEXIBLE STRUCTURE

引用

JOURNAL OF GUIDANCE control AND DYNAMICS 1993年第1期16卷 9-13页

作者： IH, CHC BAYARD, DS AHMED, A WANG, SJ Jet Propulsion Laboratory California Institute of Technology Pasadena California 91109

A six-input/six-output multivariable adaptive controller is used to control a large three-dimensional flexible structure experiment. For this purpose, the Jet Propulsion Laboratory Large Spacecraft control Laboratory antenna-like experiment structure is used, with instrumentation distributed on both the hub and the ribs. This represents a significant increase in complexity relative to earlier adaptive control experiments performed on the same structure using a two-input/two-output setup with instrumentation on the hub alone [Ih, C.-H. C., Bayard, D. S., Wang, S. J., and Eldred, D. B., ''adaptive control Experiment with a Large Flexible Structure,'' Proceedings of the AIAA Guidance, Navigation, and control Conference (Minneapolis, MN), AIAA, Washington, DC, Aug. 1988 (AIAA Paper 88-4153)]. The increase in instrumentation significantly increases spatial controllability and excitation and control of a much larger set of modes. This paper documents multivariable adaptive control experiments on this structural configuration and discusses many of the associated design and implementation issues required for successful operation.

关键词： Flexible Structures adaptive control algorithm Jet Propulsion Laboratory Spacecraft control Antennas Extended Kalman Filter Finite Element Analysis Bounded Input Bounded Output Structural Response Human In The Loop

来源：评论

学校读者我要写书评

暂无评论

Feedback control for deep brain stimulation for motor disorders

引用

HEALTHCARE TECHNOLOGY LETTERS 2020年第3期7卷 72-75页

作者： McDermott, Hugh J. Sinclair, Nicholas C. Bion Inst East Melbourne Vic 3002 Australia Univ Melbourne Med Bion Dept East Melbourne Vic Australia

Deep brain stimulation (DBS) is an effective treatment for many people living with Parkinson's disease (PD). Although the primary treatment for PD is based on medications, disease progression eventually leads to inadequate symptom control. DBS provides benefits by alleviating motor dysfunctions such as muscle rigidity and tremor. DBS devices deliver electric pulse trains into specific brain regions via implanted electrodes. Existing DBS systems usually provide continuous stimulation with constant settings of parameters such as the amount of charge delivered per pulse. However, PD is characterised by fluctuations in the severity and frequency of impairments. DBS would be improved if stimulation settings were adjusted automatically in response to each patient's ever-changing needs. This requires a device incorporating sensing of signals that estimate the severity of motor impairment linked to an adaptive control algorithm that optimises therapeutic stimulation. Several types of signals are candidates for this function. Spontaneous local field potentials recorded by the DBS electrodes have shown promise in some experimental studies of adaptive DBS. More recently, DBS-evoked potentials have been reported. In particular, evoked resonant neural activity has properties including a larger amplitude than spontaneous potentials, suggesting it may be a suitable feedback signal to control adaptive DBS.

关键词： diseases biomedical electrodes feedback prosthetics brain medical disorders patient treatment microelectrodes bioelectric potentials muscle neurophysiology deep brain stimulation motor disorders Parkinson disease PD primary treatment disease progression inadequate symptom control motor dysfunctions muscle rigidity tremor DBS devices electric pulse trains specific brain regions DBS systems continuous stimulation motor impairment adaptive control algorithm therapeutic stimulation DBS electrodes adaptive DBS DBS-evoked potentials feedback signal feedback control

来源：评论

学校读者我要写书评

暂无评论

Advantage of cooperative traffic light control algorithms

引用

IET INTELLIGENT TRANSPORT SYSTEMS 2017年第7期11卷 379-386页

作者： Blokpoel, Robbin Niebel, Wolfgang Dynniq Res Dept Amersfoort Netherlands German Aerosp Ctr Inst Transport Res Cologne Germany

Contemporary traffic light control systems rely on sensors for detection of traffic which are costly in purchase, installation and maintenance. Emerging cooperative technology offers an attractive alternative where only one road side unit per intersection is required, instead of several infrastructure sensors per lane. However, studies showed that traffic control with cooperative detection requires a penetration rate of at least 20% to function effectively. To show the potential of cooperative traffic control, this study presents three algorithms: (i) the SWARM control algorithm, which is designed to work with very low penetration rates;(ii) an extension to the adaptive control algorithm, ImFlow, which uses cooperative data for enhanced queue modelling;and (iii) an ImFlow extension to stabilise green planning to enable green light optimal speed advice. The results from micro-simulation show a 7.8% improvement for stops and delay time over traditional adaptive control for Swarm, and 14.9% for Cooperative ImFlow. Adding planning stabilisation reduced the average perceived change for end users from 9.0-2.3%, without performance loss for the overall traffic flow. This shows the large potential of cooperative traffic control.

关键词： road traffic control control system synthesis adaptive control stability cooperative traffic light control algorithms traffic detection road intersection SWARM control algorithm design penetration rates adaptive control algorithm ImFlow enhanced queue modelling green planning stabilisation optimal green light speed microsimulation stop time improvement delay time improvement average perceived change

来源：评论

学校读者我要写书评

暂无评论

A Study on adaptive Rate control Scheme

A Study on Adaptive Rate Control Scheme

引用

2015 IEEE International Conference on Computational Intelligence & Communication Technology (CICT 2015)

作者： Tan, Shizhe Sun, Fajiang Zhang, Jing Ocean Univ China Dept Elect Engn Qingdao 266100 Peoples R China

ISBN: (纸本)9781479960224

On the base of research on real time transport protocol and real time transport control protocol (RTP/RTCP), a flow adaptive control algorithm was proposed. The new algorithm chooses different growth factors according to the current state of the network. It aims at enhancing the stabilization of RTP flow, decreasing the jitter and utilizing network bandwidth efficiently.

关键词： adaptive control algorithm RTP/RTCP network bandwidth

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：