This paper deals with a new method of finite-dimensional control for a class of mechanically flexible systems subject to random disturbances, by reducing the distributed parameter system to a finite-dimensional one. T...
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This paper deals with a new method of finite-dimensional control for a class of mechanically flexible systems subject to random disturbances, by reducing the distributed parameter system to a finite-dimensional one. The principal approach is to regard the observation spillover due to the uncontrolled modes as a colored observation noise and construct an estimator. Under certain conditions related to the number of sensors, this approach ensures that the direct decoupling of controller and estimator and that the effect of observation spillover can be reduced so that the stability of the resulting system is guaranteed. Simulation studies for a simply supported or free-free beam are provided.
Model matching control to unmodeled high frequency dynamic is studied using singular perturbation theory. Both the frequency-domain method and sampled-data control approach are examined. It is shown that the controlle...
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Model matching control to unmodeled high frequency dynamic is studied using singular perturbation theory. Both the frequency-domain method and sampled-data control approach are examined. It is shown that the controller designed on the basis of reduced-order model is able to make the full system match the stable model.
Stabilization problem of discrete two-time-scale systems via block implementation is considered in this paper. Block dynamical equations for the original system and slow and fast subsystems are examined. It is shown t...
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Stabilization problem of discrete two-time-scale systems via block implementation is considered in this paper. Block dynamical equations for the original system and slow and fast subsystems are examined. It is shown that the eigenvalue assignment problem for subsystems, both in state and output feedback cases, can be exploited to stabilize the full system by adding certain extra compensators.
This paper deals with the linear model-following control (LMFC) of a class of discrete systems which have the two-time-scale (TTS) property. It is shown that, under certain sufficient conditions, the proposed reduced-...
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This paper deals with the linear model-following control (LMFC) of a class of discrete systems which have the two-time-scale (TTS) property. It is shown that, under certain sufficient conditions, the proposed reduced-order LMFC can force the slow subsystem of the plant to follow the stable model asymptotically. Both state feedback and observer-based feedback control are considered. An example [8] is used to demonstrate the derived schemes. The design algorithms of the controllers are summarized in the conclusion.
The problem of rudder induced roll motions in a modern warship is considered in this paper. The development of a fuzzy controller is discussed which uses roll and roll rate as input and fin demand as output in order t...
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The problem of rudder induced roll motions in a modern warship is considered in this paper. The development of a fuzzy controller is discussed which uses roll and roll rate as input and fin demand as output in order to eliminate the undesired induced roll. Owing to the non-linear warship roll dynamics, it was necessary for the fuzzy controller to have multiple output fuzzy set options. The choice of output fuzzy set depending on the speed of the ship and the rudder demand. Digital computer simulation results show that the fuzzy controller can successfully suppress the unwanted roll motion and thus, it helps to improve the operational efficiency of the warship.
This paper describes a technique to partition power networks into cluster of nodes and transmission elements. The objective is to obtain smaller and semi-independent sub-networks to jmprove the computational efficienc...
This paper describes a technique to partition power networks into cluster of nodes and transmission elements. The objective is to obtain smaller and semi-independent sub-networks to jmprove the computational efficiency of some steady-state power system functions such as, for instance, security and reactive power controls, and contingency analysis. The proposed technique is based on the projection of the position of the nodes onto an r -dimensional sub-space. The coordinates of the nodes are determined through an eigenvalue-based approach, and cluster of closely related nodes are calculated. Adjustment on the partitions are performed by transferring nodes from one cluster to another, so that every derived sub-network is entirely connected. Test results have been obtained for the IEEE 24-bus reliability test system and IEEE 118-bus test system
An automatic printed circuit board (PCB) inspection system called PI/l, is described in this paper. The system can inspect PCB artwork and inner layers to find trace faults such as open circuits, short circuits, pin h...
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The no.2 reversing mill installed in the cold rolling plant of the Wakayama steel works (Japan) is described. It has been built with the aim of ensuring high-precision strip gauge and flatness. It includes a fully dig...
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The no.2 reversing mill installed in the cold rolling plant of the Wakayama steel works (Japan) is described. It has been built with the aim of ensuring high-precision strip gauge and flatness. It includes a fully digitized AC variable-speed drive system and advanced technology that improves gauge accuracy. The specifications and features of the mill are set forth, the characteristics of the electrical equipment are discussed, and the gauge controlsystem is examined in more detail.< >
Almost 25 years ago, the U.S. Navy committed to gas turbines for propulsion and electrical power generation for surface combatants. Jet engines from the aerospace industry were “marinized” and specified for several ...
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Almost 25 years ago, the U.S. Navy committed to gas turbines for propulsion and electrical power generation for surface combatants. Jet engines from the aerospace industry were “marinized” and specified for several designs. Today, there are over one hundred gas turbine powered surface ships; almost half also have gas turbine generators. This fundamental change, notably from steam to gas turbine power, brought with it a new philosophy in the way prime movers are controlled and monitored. Unmanned engineering spaces were a fundamental part of the new design. Direct thrust control in the hands of the helmsman was possible. Possibly the most profound effect was the introduction of electronics in the main engineering spaces on a large scale. Data buses for data logging and bell logging were used as a means to reduce the tedium of normal watch standing. Gas turbine machinery controlsystems have entered a second generation with the introduction of the DDG-51 class destroyer and the AOE-6 supply ship. Hard-wired analog interfaces have given way to digital interfaces over asynschronous multiplexed data buses. Dedicated pushbuttons and indicators have given way to keyboards and plasma displays. Single use microprocessors with firmware coding have given way to standard microcomputers and general high order language (HOL) software code. This paper will trace the controlsystems' evolution from the Spruance and Perry classes to today's gas turbine designs. An attempt will be made to draw a sense of direction from this evolution. An in-depth explanation of the DDG-51 controlsystem will be offered, as well as suggestions as to the future of controlsystems for gas turbine ships. Particular emphasis will be placed on the man-machine interface and the maintenance philosophy for both the controlsystem hardware and software.
A combined frequency and time domain design technique is described for a class of multivariable feedback systems containing a set of coupled nonlinear elements of any general multivalued form. The parameter of the com...
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A combined frequency and time domain design technique is described for a class of multivariable feedback systems containing a set of coupled nonlinear elements of any general multivalued form. The parameter of the compensator is initially derived from the frequency domain analysis and automatically adjusted by the numerical synthesis routine in order to meet specified time domain performance. The method employs a combined analytical and synthesis procedures and provides a powerful tool in the design of a wide class of nonlinear multivariable feedback systems. Example is presented to demonstrate the efficiency of the proposed design technique.
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