This paper deals with the issue of control with a constraint that in the controlled system certain variables remain free. By free, we mean that the variables are allowed to assume any trajectory. These variables can b...
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This paper deals with the issue of control with a constraint that in the controlled system certain variables remain free. By free, we mean that the variables are allowed to assume any trajectory. These variables can be interpreted as disturbances. The question of which controlled behaviors are a priori possible such that the controlled behaviors do not impose any constraints on the disturbance variables is addressed and solved. Certain generalities are imposed on the problem in the sense that a controller can act on only certain variables called control variables, while the performance specification is in terms of a different variable called the to-be-controlled variable. Another issue that we deal with is the notion of compatibility of such controllers. Further, the issue of controllability of the controller itself is dealt with, for the specific control problems of pole placement and stabilization. We use the behavioral approach to address these issues. In this setup control is considered as interconnection of two systems without distinguishing the variables of each system into inputs and outputs.
A dual-arm robotic manipulator needs to maintain its end-effectors' orientations with reference to each other as defined by the task constraints at various locations. To give one example, the task of operating a p...
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A dual-arm robotic manipulator needs to maintain its end-effectors' orientations with reference to each other as defined by the task constraints at various locations. To give one example, the task of operating a pair of pliers by rigidly grasping its handles will require that the orientation of the two end-effectors with respect to each other should vary as a function of their respective locations. Due to the wrist joint range limitations, dexterity is very limited and it may not be possible to achieve a desired maneuver along a desired trajectory. We present here a systematic approach to judge the feasibility of such demands and a method to find other reasonable target trajectories or orientations. The approach here is based on simple geometry with little computation load.
In data publishing, the owner delegates the role of satisfying user queries to a third-party publisher. As the publisher may be untrusted or susceptible to attacks, it could produce incorrect query results. In this pa...
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ISBN:
(纸本)9781595930606
In data publishing, the owner delegates the role of satisfying user queries to a third-party publisher. As the publisher may be untrusted or susceptible to attacks, it could produce incorrect query results. In this paper, we introduce a scheme for users to verify that their query results are complete (i.e., no qualifying tuples are omitted) and authentic (i.e., all the result values originated from the owner). The scheme supports range selection on key and non-key attributes, project as well as join queries on relational databases. Moreover, the proposed scheme complies with access control policies, is computationally secure, and can be implemented efficiently. Copyright 2005 ACM.
An algorithm is proposed for automation of the prefilter design step of Horowitz's quantitative feedback theory (QFT) to robust feedback system synthesis. The proposed algorithm uses interval global optimization t...
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Recently, two versions of the so-called Taylor-Bernstein (TB) form having the property of higher order convergence were proposed in [5] and [10]. However, in many application problems, both these TB forms encounter di...
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Recently, two versions of the so-called Taylor-Bernstein (TB) form having the property of higher order convergence were proposed in [5] and [10]. However, in many application problems, both these TB forms encounter difficulties in computing the range enclosures for some domain widths, due to excessive memory and/or time requirements. In this paper, we present a combined TB form that is more successful in computing the range enclosures as the domain shrinks from large to small widths. We test and compare the performance of the proposed form with those of the existing TB forms, the Taylor model of Berz et al. [1], and the simple natural inclusion function form. For the testing, we consider six benchmark examples with dimensions varying from 1 to 6. The results of the tests show that the proposed combined TB form is indeed more effective than the existing TB forms and the Taylor model, over the entire range of domain widths considered.
The aim of this paper is to develop a new method for sliding mode control of a class of discrete-time nonlinear systems that are feedback linearizable. One advantage of this method is that it allows the use of the rec...
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Recent results on higher order sliding mode control algorithms are applied to a permanent magnet (PM) Stepper Motor. Use of Sliding Mode control of an order higher than the relative degree of the sliding surface with ...
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Power System Stabilizers (PSSs) are added to excitation systems to enhance the damping during low frequency oscillations. In this paper, the design of decentralized PSSs for 10 machines with 39 buses using fast output...
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ISBN:
(纸本)0780388739
Power System Stabilizers (PSSs) are added to excitation systems to enhance the damping during low frequency oscillations. In this paper, the design of decentralized PSSs for 10 machines with 39 buses using fast output sampling feedback via reduced order model is proposed. The nonlinear model of multimachine system is linearized at a particular operating point and a linear model is obtained. Using model reduction technique, lower order model is obtained from the higher order model and for this reduced model a stabilizing state feedback gain is obtained. Using aggregation technique, state feedback gain is obtained for the higher order model. A decentralized fast output sampling feedback gain which realizes this state feedback gain is obtained using LMI approach. This method does not require state of the system for feedback and is easily implementable. This decentralized fast output sampling control via reduced order model is applied to non-linear plant model of the multimachine. This method gives very good results for the design of Power System Stabilizers.
This paper discusses the spatial controller design with periodic output feedback for a 540 MWe PHWR. the spatial model of the reactor developed in (Tiwari, 1999) is augmented with models for variation of coolant and f...
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Power system stabilizers (PSS) are added to excitation systems to enhance the damping during low frequency oscillations. In this paper, the design of decentralized PSS for 10 machines with 39 buses using fast output s...
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Power system stabilizers (PSS) are added to excitation systems to enhance the damping during low frequency oscillations. In this paper, the design of decentralized PSS for 10 machines with 39 buses using fast output sampling feedback via reduced order model is proposed. The nonlinear model of multi-machine system is linearized at a particular operating point and a linear model is obtained. Using model reduction technique, lower order model is obtained from the higher order model and for this reduced model a stabilizing state feedback gain is obtained. Using aggregation technique, state feedback gain is obtained for the higher order model. A decentralized fast output sampling feedback gain which realizes this state feedback gain is obtained using LMI approach. This method does not require state of the system for feedback and is easily implementable. This decentralized fast output sampling control via reduced order model is applied to non-linear plant model of the multi-machine. This method gives very good results for the design of power system stabilizers.
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