Experimental Demonstration of Precision Control of a Deployable Optics Structure

2002 ◽  
Vol 124 (3) ◽  
pp. 441-450 ◽  
Author(s):  
R. Scott Erwin ◽  
Karl Schrader ◽  
Ruth L. Moser ◽  
Steven F. Griffin
Keyword(s):  
Control System ◽  
Structural Control ◽  
Level Control ◽  
Precision Control ◽  
Research Issues ◽  
Optical Surfaces ◽  
Point Tracking ◽  
High Bandwidth ◽  
And Performance ◽  
System 1

This paper presents the development, design, and implementation of a precision control system for a large, sparse-aperture space-deployable telescope testbed. Aspects of the testbed and laboratory environment relevant to nanometer-level control and performance objectives are provided. There are four main objectives of the control system: 1) reduction of natural resonances of the supporting structure, 2) rejection of tonal disturbances, 3) tip, tilt, and piston set-point tracking for optical surfaces, and 4) reduction in settling time of optical surfaces after an impulsive slew-type disturbance. The development of a three-input, three-output, high-bandwidth structural control system for the testbed is presented, and experimental data demonstrating that all objectives were attained is provided. The paper concludes with a discussion of the results and a description of research issues remaining to be addressed.

Design and Performance of Passive Control System for Gas-Liquid Cylindrical Cyclone Separators

1998 ◽  
Vol 120 (1) ◽  
pp. 49-55 ◽  
Author(s):  
R. S. Mohan ◽  
S. Wang ◽  
O. Shoham ◽  
G. E. Kouba
Keyword(s):  
Control System ◽  
Passive Control ◽  
Level Control ◽  
Control Approach ◽  
Flow Energy ◽  
External Power Source ◽  
Cylindrical Cyclone ◽  
And Performance ◽  
Operational Envelope ◽  
Classical Control

The performance of gas-liquid cylindrical cyclone (GLCC) separators can be improved by reducing or eliminating liquid carryover into the gas stream or gas carryunder through the liquid stream, utilizing a suitable liquid level control. In this study, a new passive control system has been developed for the GLCC, in which the control is achieved by utilizing only the liquid flow energy. A passive control system is highly desirable for remote, unmanned locations operated with no external power source. Salient features of this design are presented here. Detailed experimental and modeling studies have been conducted to evaluate the improvement in the GLCC operational envelope for liquid carryover with the passive control system. The results demonstrate that a passive control system is feasible for operation in normal slug flow conditions. The advantage of a dual inlet configuration of the GLCC is quantified for comparative evaluation of the passive control system. The results of this study could form the basis for future development of active control systems using a classical control approach.

scholarly journals Reduction of single DC bus capacitance in photovoltaic cascaded multilevel converter

2020 ◽  
Vol 11 (3) ◽  
pp. 1660
Author(s):  
Turki Kahawish Hassan
Keyword(s):  
Control System ◽  
Harmonic Distortion ◽  
Voltage Control ◽  
Partial Shading ◽  
Point Tracking ◽  
High Bandwidth ◽  
Dc Voltage Control ◽  
Dc Bus ◽  
Bus Voltage ◽  
Power Point

<span lang="EN-US">This paper presented single DC bus single phase seven level cascaded H-bridge (CHB) inverter for multi-panel photovoltaic grid-connected applications. A single DC bus supplying flyback converters to produce DC link voltages for CHB cells is suggested. A balanced operation of CHB inverter cells is obtained irrespective to power unbalance occurred by individual maximum power point tracking boost converter of photovoltaic (PV) panels due to the non-uniform irradiation and partial shading. A DC bus voltage control system with addition of estimated DC bus ripple voltage to the reference is proposed to eliminate the second order harmonic contained in the feedback voltage of DC bus enabling to design high bandwidth of DC voltage control loop. This produces fast dynamic response, low total harmonic distortion (THD) of grid current and smaller DC bus capacitance. Mathematical modeling of bus voltage control system is presented. PSIM simulation program is used and the simulation results are obtained to validate the proposed control system.</span>

Determinants of Control System Design in Divisionalized Firms

2004 ◽  
Vol 79 (3) ◽  
pp. 545-570 ◽  
Author(s):  
Margaret A. Abernethy ◽  
Jan Bouwens ◽  
Laurence van Lent
Keyword(s):  
Control System ◽  
System Design ◽  
Performance Measures ◽  
Simultaneous Equation ◽  
Equation Model ◽  
Control System Design ◽  
Information Asymmetries ◽  
Endogenous Variables ◽  
And Performance ◽  
Using Data

We investigate two determinants of two choices in the control system of divisionalized firms, namely decentralization and use of performance measures. The two determinants are those identified in the literature as important to control system design: (1) information asymmetries between corporate and divisional managers and (2) division interdependencies. We treat decentralization and performance measurement choices as endogenous variables and examine the interrelation among these choices using a simultaneous equation model. Using data from 78 divisions, our results indicate that decentralization is positively related to the level of information asymmetries and negatively to intrafirm interdependencies, while the use of performance measures is affected by the level of interdependencies among divisions within the firm, but not by information asymmetries. We find some evidence that decentralization choice and use of performance measures are complementary.

scholarly journals Information Quality Assessment for Data Fusion Systems

Data ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 60
Author(s):  
Miguel A. Becerra ◽  
Catalina Tobón ◽  
Andrés Eduardo Castro-Ospina ◽  
Diego H. Peluffo-Ordóñez
Keyword(s):  
Data Fusion ◽  
Information Quality ◽  
Engineering Process ◽  
Comprehensive Description ◽  
Research Issues ◽  
Fusion Systems ◽  
General Data ◽  
Fusion Engineering ◽  
And Performance ◽  
Key Aspects

This paper provides a comprehensive description of the current literature on data fusion, with an emphasis on Information Quality (IQ) and performance evaluation. This literature review highlights recent studies that reveal existing gaps, the need to find a synergy between data fusion and IQ, several research issues, and the challenges and pitfalls in this field. First, the main models, frameworks, architectures, algorithms, solutions, problems, and requirements are analyzed. Second, a general data fusion engineering process is presented to show how complex it is to design a framework for a specific application. Third, an IQ approach, as well as the different methodologies and frameworks used to assess IQ in information systems are addressed; in addition, data fusion systems are presented along with their related criteria. Furthermore, information on the context in data fusion systems and its IQ assessment are discussed. Subsequently, the issue of data fusion systems’ performance is reviewed. Finally, some key aspects and concluding remarks are outlined, and some future lines of work are gathered.

Sign in / Sign up

Export Citation Format

Share Document