Distributed Control Technique Research Articles

Fast algorithms for PDEs in simple and complex geometries

AbstractA brief review of our fast algorithms is given in this short paper. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

3307 三次元適応トラス構造の分散型姿勢制御法の実験的検討

This paper suggests posture control technique of manipulator-like variable geometry truss (VGT) structures by distributed control rule. In the control problem of VGT posture and position at the tip, it is inefficient and difficult to decide control values of large scale control problem by central control. Therefore the distributed control technique is adopted for this problem. The distributed control problem of VGT is decomposed into a set of optimization sub-problems which consist of a objective function of control energy and tip positioning geometrical constraints of VGT tip. Each control value of length adjustable members is determined by solving each optimization sub-problem independently and separately. The validity of suggested technique is confirmed by the experiment.

Scalable 10 Gbit/s 4 × 2 0.25 µm CMOS/SIMOXATM switch LSI circuitbased on distributed contention control

A scalable 10 Gbit/s 4 × 2 ATM switch LSI circuit has been fabricated. It employs a new distributed contention control technique that makes the LSI circuit expandable. To increase the LSI circuit throughput, 0.25 µm CMOS/SIMOX (separation by implanted oxygen) technology is used. It allows the LSI circuit to offer 221 I/O pins, an operating speed of 1.25 Gbit/s and 7 W power consumption.

A 10-Gb/s (1.25 Gb/s×8)4×2 0.25-μm CMOS/SIMOX ATM switch based on scalable distributed arbitration

This paper presents the design and implementation of a scalable asynchronous transfer mode switch. We fabricated a 10-Gb/s 4/spl times/2 switch large-scale integration (LSI) that uses a new distributed contention control technique that allows the switch LSI to be expanded. The developed contention control is executed in a distributed manner at each switch LSI, and the contention control time does not depend on the number of connected switch LSI's. To increase the LSI throughput and reduce the power consumption, we used 0.25-/spl mu/m CMOS/SIMOX (separation by implanted oxygen) technology, which enables us to make 221 pseudo-emitter-coupled-logic I/O pins with 1.25-Gb/s throughput. In addition, power consumption of 7 W is achieved by operating the CMOS/SIMOX gates at -2.0 V. This consumption is 36% less than that of bulk CMOS gates (11 W) at the same speed at -2.5 V. Using these switch LSI's, an 8/spl times/8 switching multichip module with 80-Gb/s throughput was fabricated with a compact size.

Automatic control and management of electrostatic precipitator

The efficient operation of an electrostatic precipitator (ESP) in practice depends upon many variables, such as charging method, particle size, gas flow, temperature, dust resistivity, etc. With air pollution control requirements becoming increasingly stringent, it is essential to closely monitor and accurately control the key parameters of an ESP control system. The efficient functioning of an ESP normally means minimizing power consumption and maximizing dust collection. Several control strategies can be adopted to meet this broad requirement. In this paper, a distributed control technique of an ESP, which uses the actual dust emission and boiler load as feedback inputs has been explained. The electrostatic precipitator management system, which is a system designed by Bharat Heavy Electricals Ltd., Hyderabad, India, to meet the above control strategies using the distributed architecture to achieve efficient ESP operation is also described.

A robot manipulator by a distributed control approach

A robot manipulator system employing a distributed control technique is described. Although much theoretical research has suggested the importance of distributed control in robot manipulation, very few manipulator systems of this kind have been actually proposed. The present manipulator system is realized by assigning a single 8-bit microprocessor at each of the four joints of the manipulator. Initialized by the central 16-bit processor, these microprocessors calculate their respective joint angles by mutually exchanging the information necessary for the calculation via the central processor, and give motion to their respective arms. Experimental results show successful achievement of the distributed control.

分散制御方式を用いたロボットマニピュレータ

A robot manipulator system employing a distributed control technique is described. Although many theoretical researches suggest the importance of distributed control in robot manipulation, very few manipulator systems of this kind have been actually proposed. The present manipulator system is realized by assigning a single 8-bit microprocessor at each of the four joints of the manipulator. Initialized by the central 16-bit processor, these microprocessors calculate their respective joint angles by exchanging mutually the information necessary for the calculation via the central processor, and give motion to their respective arms. Experimental results show successful achievement of the distributed control.

Matrix Operations on a Multicomputer System with Switchable Main Memory Modules and Dynamic Control

This paper presents an analysis and evaluation of the performance of a multicomputer system (SM3) in supporting two basic matrix operations, namely multiplication and inversion. The system supports the efficient execution of the above mentioned operations by 1) achieving a high-bandwidth data transfer among computers by switching main memory modules, 2) supporting network partitioning, 3) employing a hardware communication and synchronization scheme, 4) using a distributed control technique, and 5) providing means to dynamically transfer control. Timing equations are derived and evaluated in an attempt to analyze the performance. Different cases which arise due to the relative sizes of memory modules and matrices during matrix multiplication are analyzed. The cases of partial and maximal pivoting during inversion are also analyzed. The SM3 system is compared quantitatively and qualitatively to a hypercube architecture.

The Design and Simulation of a Mobile Radio Network with Distributed Control

A new architecture for mobile radio networks, called the linked cluster architecture, is described, and methods for implementing this architecture using distributed control techniques are presented. We illustrate how fully distributed control methods can be combined with hierarchical control to create a network that is robust with respect to both node loss and connectivity changes. Two distributed algorithms are presented that deal with the formation and linkage of clusters and the activation of the network links. To study the performance of our network structuring algorithms, a simulation model was developed. The use of Simula to construct, software simulation tools is illustrated. Simulation results are shown for the example of a high frequency (HF) intratask force (ITF) communication network.

Microcomputer-Based Controls for Continuous Casting

The continuous casting of steel eliminates many processing steps, thus allowing savings in time, energy, and processing costs. In this process a moving strand of steel is partially solidified in a water-cooled mold and subsequently cooled to complete solidification by intensive-cooling water sprays. Control of the cooling sprays is complex, requiring distributed control techniques, which are not readily implemented by analog means. Therefore, digital computer control systems have been developed for this purpose. In the past these systems have used a minicomputer in a supervisory control mode to provide optimum water-flow setpoints to conventional proportional plus integral analog controllers. This approach has given satisfactory results, but initial hardware and software costs have been high, and maintenance requirements, particularly in the computer/controller interface hardware, have been excessive. US Steel is currently testing a microcomputer-based control system which has the potential for resolving these problems. This system provides all the control features normally used as well as direct digital control (ddc) of cooling water flows, thus eliminating the need for analog controllers. Experience to date indicates that this new approach will provide increased reliability along with a significant reduction in equipment and maintenance costs.

The 80's—Microprocessors, Distributed Control and Advanced Instrumentation for the Minerals Industry

This paper reviews the historical development of process instrumentation and control. It discusses some of the major innovations as they relate to the mineral industry. It includes a review of the different control philosophies which have led to the development of distributed control techniques. It concludes with a series of projections as to what can be expected in the future.

Long term developments in switching

Developments are considered under the headings (i) connection techniques, (ii) control techniques, (hi) interaction of switching and transmission techniques, (iv) facilities offered, and (v) connecting network topology. In each topic, there are open questions. The major forecasts are: (i) the extensive use of electronic digital multiplex connecting networks, compatible with digital transmission systems; (ii) the introduction of optical connecting techniques, which offer both compatibility with optical transmission and some interesting new possibilities for the size and configuration of switches; (iii) the extensive use of stored program control; (iv) the supplementation of central processors by distributed control techniques for the common operational procedures, probably using microprocessors; and (v) the widespread use of semiconductor integrated circuits both for connection and control functions.