Decentralized Control of Structural Acoustic Radiation

2001 ◽  
Author(s):  
Kenneth D. Frampton
Keyword(s):  
Control System ◽  
Decentralized Control ◽  
Large Scale ◽  
Acoustic Radiation ◽  
Electrical Power ◽  
Computational Effort ◽  
Centralized Control ◽  
Mems Devices ◽  
Sensors And Actuators ◽  
Recent Developments

Abstract Although the application of active control to vibrations has been investigated from many years, the extension of this technology to large-scale systems has been thwarted, in part, by an overwhelming need for computational effort, data transmission and electrical power. This need has been overwhelming in the sense that the potential applications are unable to bear the power, weight and complex communications requirement of large-scale centralized control systems. Recent developments in MEMS devices and networked embedded devices have changed the focus of such applications from centralized control architectures to decentralized ones. A decentralized control system is one that consists of many autonomous, or semi-autonomous, localized controllers called nodes, acting on a single plant, in order to achieve a global control objective. Each of these nodes has the following capabilities and assets: 1) a relatively limited computational capability including limited memory, 2) oversight of a suite of sensors and actuators and 3) a communications link (either wired or wireless) with neighboring or regional nodes. The objective of a decentralized controller is the same as for a centralized control system: to maintain some desirable global system behavior in the presences of disturbances. However, decentralized controllers do so with each node possessing only a limited amount of information on the global systems response. Exactly what information each node has access to, and how that information is used, is the topic of this investigation.

scholarly journals Design of Centralized PI Control System for Two Variable Processes based on Root Locus Technique

2019 ◽  
Vol 9 (1) ◽  
pp. 4851-4855
Keyword(s):  
Control System ◽  
System Design ◽  
Decentralized Control ◽  
Pi Control ◽  
Control System Design ◽  
Centralized Control ◽  
Single Variable ◽  
Root Locus ◽  
Input And Output ◽  
Simulation Results

This paper describes the design of centralized controller for two variable processes. The two variable process structures are somehow different from the single variable processes. This difference is occurred because of interrelations between the variables present in the process. Hence, when a controller is planned for such systems, the relations amid the variables must be taken into consideration. This process is done in decentralized control system design. But decentralized control system works well when the interrelations between the variables are simple. If the interaction is strong, then the centralized control system is preferred since it uses a controller for each pair of input and output variables. The controller used in main diagonal works for improving the servo performance and off diagonal controller reduces the interrelation effect. So the performance is improved by minimizing the interrelation effects. The design process is easy to understand by field engineers working in industries. The simulation results are included in this paper to specify the efficacy of the proposed scheme.

scholarly journals A Decentralized, Flat-Structured Control System for Chiller Plants

2019 ◽  
Vol 9 (22) ◽  
pp. 4811 ◽  
Author(s):  
Dong He ◽  
Qingyu Xiong ◽  
Xuyang Zhang ◽  
Yunchuang Dai ◽  
Ziyan Jiang
Keyword(s):  
Energy Efficiency ◽  
Control System ◽  
Decentralized Control ◽  
Control Method ◽  
Control Strategies ◽  
Measured Data ◽  
Self Organization ◽  
Centralized Control ◽  
Self Recognition

This paper presents a novel control system for chiller plants that is decentralized and flat-structured. Each device in chiller plant system is fitted with a smart node. It is a smart agent, which collects, handles and sends out information to its neighbours. All the smart nodes form a network that can realize self-organization and self-recognition. Different kinds of control strategies can be converted into series of decentralized computing processes carried on by the smart nodes. The principle and mechanism of this decentralized, flat-structured control system for chiller plants are described in detail. Then a case study is presented to show how to build the decentralized, flat-structured control system actually. The measured data shows that the decentralized control method is energy efficiency. Moreover, it is much more flexible and scalable compared with the traditional centralized control method.

Hierarchical, decentralized control system for large-scale smart-structures

2014 ◽  
Vol 23 (8) ◽  
pp. 085037 ◽  
Author(s):  
Stephan Algermissen ◽  
Tim Fröhlich ◽  
Hans Peter Monner
Keyword(s):  
Control System ◽  
Decentralized Control ◽  
Large Scale ◽  
Smart Structures

Synchronous Controller of LED Video Displays and LED Lighting Compatible

2011 ◽  
Vol 383-390 ◽  
pp. 6959-6963
Author(s):  
Jian She Sun ◽  
Xiao Ning Feng ◽  
Yi Fei Sun ◽  
Hui Zhao
Keyword(s):  
Control System ◽  
High Speed ◽  
Large Scale ◽  
Centralized Control ◽  
Fiber Communication ◽  
Protocol Conversion ◽  
Wide Range ◽  
Lighting Systems ◽  
Control Port ◽  
Control Distance

The development of a large display and can control a variety of compatible lighting control system, the system is suitable for wide range control distance. Can be widely used in modern college park, landscape building, business building and landscaping all buildings, publicity, service, advertising and other large screen and lighting systems. Using large-scale high-speed FPGA technology, Gigabit fiber communication technology, through a multi-level processing and protocol conversion, can be terminal for the different display mode (divided into static, 2 sweep, sweep 4, 8, sweep, sweep five kinds of 16), data in the order, alignment methods, control methods, the preparation of their own in the FPGA, the protocol conversion module, through the software are free to choose set the display terminal type, to achieve 16 control port can be controlled separately different types of display terminal. Control distance up to 5000 meters or more. Effectively address all the original control system can not be compatible, not centralized control, can not share resources and control of the key problems of distance is too short.

On the Stability of Decentralized AVC/ASAC for Large-Scale Structures

2015 ◽  
Author(s):  
Stephan Algermissen ◽  
Hans P. Monner
Keyword(s):  
Control System ◽  
Large Scale ◽  
Active Vibration Control ◽  
Underlying Structure ◽  
Noise Emission ◽  
Sensors And Actuators ◽  
Control Approach ◽  
Control Loops ◽  
Acoustic Control ◽  
The Stability

Active Vibration Control (AVC) and Active Structural Acoustic Control (ASAC) gained much attention in all kind of industries in the past. Promising results have been achieved in controlling the vibration and the noise emission/transmission of single panel structures. Especially for aircraft applications, concepts for the reduction of the turbulent boundary layer, rotor or jet noise are presented in the literature. In most cases the contributed work is focused on a single panel or a section of the fuselage/lining. However, an AVC/ASAC system can only be effective for the passengers when it is expanded to the entire fuselage structure. This expansion inevitably leads to a large number of sensors and actuators and thus to a controlled plant of high dimensions. For model-based control approaches especially, the system identification and the proof of stability would be challenging and probably not realizable. In this paper a strategy for such large-scale problems is investigated. A decentralized control approach with collocated actuator-sensor pairs is proposed. Since adjacent control loops are highly coupled by the underlying structure, special attention has to be given to the global stability of the entire control system. Instead of proving local stability and setting a global master gain, a method for the tuning of the single collocated control loops is developed that takes the cross-couplings into account. Based on data of DLR’s experimental aircraft Dornier 728, it can be shown that the new method increases the performance of the control system compared to the master-gain method.

On the stability of decentralized AVC/ASAC for large-scale structures

2017 ◽  
Vol 28 (16) ◽  
pp. 2255-2264 ◽  
Author(s):  
Stephan Algermissen ◽  
Hans Peter Monner
Keyword(s):  
Control System ◽  
Large Scale ◽  
Active Vibration Control ◽  
Underlying Structure ◽  
Noise Emission ◽  
Sensors And Actuators ◽  
Control Approach ◽  
Control Loops ◽  
Acoustic Control ◽  
The Stability

Promising results have been achieved in controlling vibration and noise emission/transmission of single panel structures using active vibration control (AVC) and active structural acoustic control (ASAC). In most cases the contributed work has focused on a single panel or a section of the fuselage/lining. However, an AVC/ASAC system can only be effective when it is expanded to the entire fuselage structure. This expansion inevitably leads to a large number of sensors and actuators. For model-based control approaches especially, the system identification and the proof-of-stability would be challenging and probably not realizable. In this article a strategy for such large-scale problems is investigated. A decentralized control approach with collocated actuator–sensor pairs is proposed. Since adjacent control loops are highly coupled by the underlying structure, special attention has to be given to the global stability of the entire control system. Instead of proving local stability and setting a global master gain, a method for the tuning of the single collocated control loops is developed that takes the cross-couplings into account. Based on data of DLR’s experimental aircraft Dornier 728, it can be shown that the new method increases the performance of the control system compared to the master-gain method.

scholarly journals Decentralized Control of a Group of Homogeneous Vehicles in Obstructed Environment

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Vyacheslav Pshikhopov ◽  
Mikhail Medvedev ◽  
Alexander Kolesnikov ◽  
Roman Fedorenko ◽  
Boris Gurenko
Keyword(s):  
Control System ◽  
Path Planning ◽  
Local Control ◽  
Decentralized Control ◽  
Control Algorithms ◽  
Centralized Control ◽  
State Variables ◽  
Dynamic Variable ◽  
Motion Modes ◽  
Unstable States

The presented solution is a decentralized control system with a minimal informational interaction between the objects in the group. During control and path planning the obstacles are transformed into repellers by the synthesized controls. The main feature distinguishing the developed approach from the potential fields method is that the vehicle moves in the fields of forces depending not only on the mutual positions of a robot and an obstacle but also on the additional variables allowing solving the problem of robot’s path planning using a distributed control system (Pshikhopov and Ali, 2011). Unlike the work by Pshikhopov and Ali, 2011, here an additional dynamic variable is used to introduce stable and unstable states depending on the state variables of the robot and the neighboring objects. The local control system of each vehicle uses only the values of its own speeds and coordinates and those of the neighboring objects. There is no centralized control algorithm. In the local control algorithms the obstacles are represented as vehicles being a part of the group which allows us to unify the control systems for heterogeneous groups. An analysis was performed that proves existence and asymptotic stability of the steady state motion modes. The preformed simulation confirms the synthesis and analysis results.

Logistics control enabled by IT – a window in the future

1998 ◽  
Vol 17 (2) ◽  
pp. 123-133
Author(s):  
M.J. Euwe ◽  
J.C. Wortmann
Keyword(s):  
Control System ◽  
Control Systems ◽  
Decentralized Control ◽  
Integral Approach ◽  
Centralized Control ◽  
Production Chain ◽  
The Past ◽  
Control Concept ◽  
Customer Control ◽  
Expected Benefits

When we look at historic developments in logistics organization and control concepts, we can conclude that the past shows an ongoing trend towards a more integral approach to achieve logistical coordination. The decentralized reorder point techniques used in the fifties gradually changed from MRP-I (sixties, seventies) to MRP-II (eighties, nineties). This trend is now extending beyond the walls of an individual factory. Companies feel a need to cooperate in the areas of logistics structures, forecasting, master scheduling and ordering. When we look to this integration challenge we can conclude that a different approach than used in the past is necessary. Since implementing a centralized control concept across companies is not possible, new developments are required in the area of decentralized control. We foresee that future control systems are able to communicate with supplier and customer control systems. Furthermore, we expect that these developments will also influence the setup of decentralized control systems within the company. Instead of having one control system with a scope that covers the entire production chain within the company, we will see a more modular approach where each sub control system covers only a part of the production system, e.g., a department. The expected benefits of this approach is that such an architecture provides departments with better opportunities to incorporate their specific planning requirements in the control system.

Decentralized Vibration Control With Networked Embedded Systems

2004 ◽  
Author(s):  
Tao Tao ◽  
Isaac Amundson ◽  
Kenneth D. Frampton
Keyword(s):  
Embedded Systems ◽  
Embedded System ◽  
Vibration Control ◽  
Control Systems ◽  
Decentralized Control ◽  
Large Scale ◽  
Scale Up ◽  
Data Communication ◽  
Sensor Data ◽  
Sensors And Actuators

The early promise of centralized active control technologies to improve the performance of large scale, complex systems has not been realized largely due to the inability of centralized control systems to “scale up”; that is, the inability to continue to perform well when the number of sensors and actuators becomes large. Now, recent advances in Micro-electro-mechanical systems (MEMS), microprocessor developments and the breakthroughs in embedded systems technologies, decentralized control systems may see these promises through. A networked embedded system consists of many nodes that possess limited computational capability, sensors, actuators and the ability to communicate with each other over a network. The aim of this decentralized control system is to control the vibration of a structure by using such an embedded system backbone. The key attributes of such control architectures are that they be scalable and that they be effective within the constraints of embedded systems. Toward this end, the decentralized vibration control of a simply supported beam has been implemented experimentally. The experiments demonstrate that the reduction of the system vibration is realized with the decentralized control strategy while meeting the embedded system constraints, such as a minimum of internode sensor data communication, robustness to delays in sensor data and scalability.

Decentralized Vibration Control in a Launch Vehicle Payload Fairing

2002 ◽  
Author(s):  
Kenneth D. Frampton
Keyword(s):  
Embedded Systems ◽  
Vibration Control ◽  
Control Systems ◽  
Large Scale ◽  
Launch Vehicle ◽  
Centralized Control ◽  
Sensors And Actuators ◽  
Acoustic Environment ◽  
Networked Embedded Systems ◽  
Payload Fairing

The vibro-acoustic environment inside a launch vehicle payload fairing is extremely violent resulting in excessive development costs for satellites and other payloads. The development of smart structures and active noise and vibration control technologies promised to revolutionize the design, construction and, most importantly, the acoustic environment within these fairings. However, the early promise of these technologies has not been realized in such large-scale systems primarily because of the excessive complexity, cost and weight associated with centralized control systems. Now, recent developments in MEMS sensors and actuators, along with networked embedded processor technology, have opened new research avenues in decentralized controls based on networked embedded systems. This work describes the development and comparison of decentralized control systems that utilize this new control paradigm. The controllers are hosted on numerous nodes, possessing limited computational capability, sensors and actuators. Each of these nodes is also capable of communicating with other nodes via a wired or wireless network. The constraints associated with networked embedded systems control that the control systems be relatively simple computationally, scalable and robust to failures. Simulations were conducted that demonstrate the ability of such a control architecture to attenuate specific structural modes.

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