检索结果-内蒙古大学图书馆

GENERIC DEVELOPMENTAL TURBOJET FUEL control

JOURNAL OF PROPULSION AND POWER 1992年第6期8卷 1258-1265页

作者： LILLEY, JS PENGELLY, SL FISHER, P USA MISSILE COMMAND REDSTONE ARSENAL AL 35898 USA BOEING DEF & SPACE GRP HUNTSVILLE AL 35898 USA

A personal computer (PC) based generic developmental fuel control system for expendable turbojet engines has been developed and demonstrated. This system provides a means of experimentally evaluating the engine hardware, fuel metering devices, control sensors, and control logic of turbojet missile propulsion systems independently of installation in the flight vehicle. The system is generic in nature to permit the evaluation of a variety of engine models (from various manufacturers), metering devices, and control algorithms with only minor adaptations. The design specifications for the fuel control system are presented. Detailed descriptions of the electronic hardware utilized are provided. A discussion of the software utilized in the system is presented. The software structure and the function of various programs are described in detail. An overview of the engine fuel control logic algorithms is given. The results of an experimental system evaluation are presented.

关键词： Turbojet Engine Propulsion System Engine control control algorithm Thermocouples Random Access Memory Wind Tunnel Models Flight Vehicle Transient Response Fuel Pump

来源：评论

学校读者我要写书评

暂无评论

Reflectivity control Devices for Continuous Momentum Management of Reaction Wheels

引用

JOURNAL OF SPACECRAFT AND ROCKETS 2022年第3期59卷 816-825页

作者： Scudiero, Andrea Biggs, James D. Polytech Univ Milan Dept Aerosp Sci & Technol I-20133 Milan Italy

This paper presents a concept for deep-space momentum management based on reflectivity control devices. These devices are placed in the far corners of the solar panels and exploit solar radiation pressure by changing their reflectively properties from specular reflection to absorption. A specialized control algorithm is developed according to an optimization problem that minimizes the difference between the feasible control and an ideal one, continuously dumping momentum from the reaction wheels while undertaking the mission. The ideal control fuses a classical quaternion tracking control law with a desaturation control law specially designed for the on-off actuation of these devices. Two case studies are considered: 1) a geostationary satellite on a geostationary orbit, and 2) a 12U CubeSat in a quasi-halo moon orbit, which demonstrate the usefulness of the concept and effectiveness of the control law.

关键词： Reaction Wheels Reflectivity Geostationary Satellites Moon Solar Radiation Closed Loop System Quaternions control algorithm Earth Attitude Dynamics

来源：评论

学校读者我要写书评

暂无评论

Rotating Object Specific Tracking Based on Orbit-Attitude Coordinated Adaptive control

引用

JOURNAL OF GUIDANCE control AND DYNAMICS 2021年第2期44卷 266-282页

作者： Zhu, Lingchao Wang, Shuquan Chinese Acad Sci Technol & Engn Ctr Space Utilizat 9 Dengzhuang South Rd Beijing 100094 Peoples R China Univ Chinese Acad Sci Beijing Peoples R China

Close-proximity tracking control of a rotating space object is investigated in this paper. The control objectives are relative position and attitude tracking and keeping, which include keeping the spacecraft stay at a certain distance above the specific face of the object, and keeping the spacecraft's certain body-fixed axis pointing to the object during the process. This problem is challenging because the desired motion of the tracking spacecraft is determined by both the object's attitude status and the relative motion between the spacecraft and the object. A nonlinear orbit-attitude coordinated adaptive tracking controller is developed to fulfill the tracking mission. The sufficient condition for the asymptotic stability is investigated. The influences of the uncertainties including the mass and inertial matrix of the spacecraft and disturbance are taken into consideration. Numerical simulations demonstrate the effectiveness of the tracking control.

关键词： Active Disturbance Rejection control Spacecraft Tracking Numerical Simulation Attitude Stabilization Earth Centered Inertial Fuel Consumption Solar Radiation Asteroids Earth control algorithm

来源：评论

学校读者我要写书评

暂无评论

ACTIVE control OF FAN NOISE FROM A TURBOFAN ENGINE

引用

AIAA JOURNAL 1994年第1期32卷 23-30页

作者： THOMAS, RH BURDISSO, RA FULLER, CR OBRIEN, WF Virginia Polytechnic Institute and State University Blacksburg Virginia 24061

A three-channel active control system is applied to an operational turbofan engine to reduce tonal noise produced by both the fan and the high-pressure compressor. The control approach is the feedforward filtered-x least-mean-square algorithm implemented on a digital signal processing board. Reference transducers mounted on the engine case provide blade passing and harmonics frequency information to the controller. Error information is provided by large area microphones placed in the acoustic far field. To minimize the error signal, the controller actuates loudspeakers mounted on the inlet to produce destructive interference. The sound pressure level of the fundamental tone of the fan was reduced using the three-channel controller by up to 16 dB over a +/- 30-deg angle about the engine axis. A single-channel controller could produce reduction over a +/- 15-deg angle. The experimental results show the control to be robust. Outside of the areas controlled, the levels of the tone actually increased due to the generation of radial modes by the control sources. Simultaneous control of two tones is achieved with parallel controllers. The fundamental and the first harmonic tones of the fan were controlled simultaneously with reductions of 12 and 5 dBA, respectively, measured on the engine axis. Simultaneous control was also demonstrated for the fan fundamental and the high-pressure compressor fundamental tones.

关键词： Adaptive control algorithm Turbofan Engines Sound Pressure Level Multiple Input Multiple Output Turbomachines Perceived Noise Level Bypass Ratio Digital Signal Processing control algorithm Anechoic Chambers

来源：评论

学校读者我要写书评

暂无评论

Adaptive control of combustion instability with on-line system identification

引用

JOURNAL OF PROPULSION AND POWER 1999年第3期15卷 383-389页

作者： Koshigoe, S Komatsuzaki, T Yang, V Aerospace Corp Los Angeles CA 90009 USA Calif State Univ Long Beach Dept Mech Engn Long Beach CA 90840 USA Penn State Univ Dept Mech Engn University Pk PA 16802 USA

In this study, an adaptive control system is developed for suppressing pressure oscillations in a generic combustor, where the unsteady flowfield associated with the combustion instability is described by a nonlinear inhomogeneous wave equation, control action is achieved by injecting auxiliary liquid fuel, and is modeled as an array of time-delayed combustion sources. The adaptive controller employs on-line system identification (SID) for robustness with respect to transient operating states, modeling uncertainties, external disturbances, and additional modes of instability that may arise in the course of control. Comparisons are made between the adaptive controller and a previously developed proportional-plus-integral (PI) controller, in terms of performance (degree of oscillation suppression, and speed with which oscillations are damped), robustness against plant parameter changes (particularly unknown factors of the auxiliary characteristics), and control-fuel mass expenditure. The adaptive controller exhibits good performance with a clear advantage over the PI controller in robustness. Also, the adaptive controller with on-line SID stabilizes the pressure oscillations without exciting additional mode(s).

关键词： Combustion Instability System Identification Combustors Solid Rocket Motor Fuel Injection Adaptive control Systems Vibration control control algorithm Signal Processing Combustion System

来源：评论

学校读者我要写书评

暂无评论

Nonlinear control Analysis of a Double-Gimbal Variable-Speed control Moment Gyroscope

引用

JOURNAL OF GUIDANCE control AND DYNAMICS 2012年第3期35卷 787-793页

作者： Stevenson, Daan Schaub, Hanspeter Univ Colorado Dept Aerosp Engn Sci Boulder CO 80309 USA

A single double-gimbal variable-speed control moment gyroscope is considered as a method for three-dimensional spacecraft attitude control. First, the system's equations of motion are developed, where gimbal and wheel accelerations. are prescribed as control inputs. The resulting necessary motor torques as well as system energy rates are computed for verification. Next, a novel control algorithm is developed from the stability constraint for reference trajectory tracking. In contrast with the control development for single-gimbal variable-speed gyros, a Newton Raphson scheme is required to solve for the desired double-gimbal variable-speed control moment gyroscope control variables because they appear in cross product and quadratic form, preventing analytical solutions. Analysis of the control theory suggests that the same torque amplification effects exist as in a single-gimbal control moment gyro, but control by a single double-gimbal variable-speed control moment gyroscope device is not robust due to potential configurations that result in control singularities. When these singularities are avoided, a simulation with successful reference trajectory tracking is achieved. Allowing double-gimbal gyros to have variable wheel speeds provides additional torquing capabilities, which is significant if failure modes are considered. As will be shown, a single double-gimbal variable-speed control moment gyroscope device can provide limited three-dimensional attitude control.

关键词： Single Gimbal control Moment Gyroscopes Nonlinear control Spacecraft Attitude Proportional control control algorithm Steering Law Electrical Energy Apollo Telescope Mount International Space Station Spacecraft Motion

来源：评论

学校读者我要写书评

暂无评论

Feed-forward control scheme to improve light-load power factor for single-stage flyback PFC converters

引用

ELECTRONICS LETTERS 2020年第1期56卷 21-22页

作者： Kim, M. Dongguk Univ Div Elect & Elect Engn Seoul 04620 South Korea

In this Letter, the author proposes a new feed-forward controller for single-stage flyback power factor correction (PFC) converters. By compensating the phase-lead effect caused by input capacitor current, the proposed feed-forward control duty improves the displacement factor as well as the distortion factor, and so the flyback PFC converter has high power quality. By means of the synchronous rectification circuit. the flyback PFC converter can operate in reverse when the negative current is required. To confirm the theoretical analysis and validity of the proposed control scheme, the author demonstrated the proposed control algorithm with 80 W flyback PFC converter prototype.

关键词： power factor power factor correction rectification power convertors feedforward control scheme light-load power factor single-stage flyback PFC converters feed-forward controller single-stage flyback power factor correction converters feed-forward control duty displacement factor distortion factor flyback PFC converter high power quality control algorithm phase-lead effect input capacitor current synchronous rectification circuit power 80.0 W

来源：评论

学校读者我要写书评

暂无评论

Feedback control of a cylinder wake low-dimensional model

引用

AIAA JOURNAL 2003年第7期41卷 1389-1391页

作者： Cohen, K Siegel, S McLaughlin, T Gillies, E USAF Acad Dept Aeronaut Colorado Springs CO 80840 USA Univ Glasgow Dept Aerosp Engn Glasgow G12 8QQ Lanark Scotland

Investigates feedback control of a cylinder wake low-dimensional model. Proper orthogonal decomposition (POD)-based flow model; Real-time implementation of closed-loop control; controllability and stability of a POD m... 详细信息

关键词： Closed Loop control Feedback control Karman Vortex Street Direct Numerical Simulation Particle Image Velocimetry Laminar Boundary Layer Navier Stokes Simulation Acoustic Properties control algorithm Nonlinear Systems

来源：评论

学校读者我要写书评

暂无评论

External shading optimal control macros for 1-and 2-piece automated blinds in European climates

引用

BUILDING SIMULATION 2015年第1期8卷 13-25页

作者： Thalfeldt, Martin Kurnitski, Jarek Tallinn Univ Technol Fac Civil Engn EE-19086 Tallinn Estonia

Dynamic external shading is considered an effective measure for improving energy performance and decreasing cooling loads. Optimal control principle is needed to minimize energy use and maximize occupants' satisfaction. We developed and described in detail optimal control macros in software IDA ICE 4.5 and simulated office building energy performances with varying facade solutions and climates over Europe. Primary energy savings between 1 and 32 kWh/m(2) were reached. Shading control to avoid glare during office hours and overheating outside work time was recommended in Tallinn and Paris. In addition shading adjustment according to room temperature during work time was necessary in Athens to minimize energy use. Also suntracking could be used in Tallinn and Paris, but PI-controllers for slat angle control were needed in Athens. Cooling load comparison of internal and external shading showed significant reduction in space cooling capacities ranging between 40% and 70%, whereas design date selection influenced cooling system design considerably besides facade solutions and orientations. Developed control macros are proposed for testing in other studies in order to find optimal control principles satisfying office workers which then could be generally implemented in design guidelines and manuals.

关键词： solar shading control algorithm energy efficiency cooling load facades offices

来源：评论

学校读者我要写书评

暂无评论

STATE-FEEDBACK control OF LONGITUDINAL COMBUSTION INSTABILITIES

引用

JOURNAL OF PROPULSION AND POWER 1992年第1期8卷 66-73页

作者： YANG, V SINHA, A FUNG, YT Pennsylvania State University University Park Pennsylvania 16802

Active control of longitudinal pressure oscillations in combustion chambers has been studied theoretically by means of a digital state-feedback control technique. The formulation is based on a generalized wave equation that accommodates all influences of combustion, mean flow, unsteady motions, and control actions. Following a procedure equivalent to the Galerkin method, a system of ordinary differential equations governing the amplitude of each oscillatory mode is derived for the controller design. The control actions are provided by a finite number of point actuators, with instantaneous chamber conditions monitored by multiple sensors. Several important control aspects, including sampling period, locations of sensors and actuators, controllability, and observability, have been investigated systematically. As a specific example, the case involving two controlled and two residual (uncontrolled) modes is studied.

关键词： Combustion Instability Feedback control System Modern control Theory Combustion Chambers Flow Conditions Shear Layers Combustion System Conservation Equations Digital control System control algorithm

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：