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82
Multichannel Blind Deconvolution: Fir Matrix Algebra And Separation Of Multipath Mixtures
, 1996
"... A general tool for multichannel and multipath problems is given in FIR matrix algebra. With Finite Impulse Response (FIR) filters (or polynomials) assuming the role played by complex scalars in traditional matrix algebra, we adapt standard eigenvalue routines, factorizations, decompositions, and mat ..."
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Cited by 74 (0 self)
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A general tool for multichannel and multipath problems is given in FIR matrix algebra. With Finite Impulse Response (FIR) filters (or polynomials) assuming the role played by complex scalars in traditional matrix algebra, we adapt standard eigenvalue routines, factorizations, decompositions, and matrix algorithms for use in multichannel /multipath problems. Using abstract algebra/group theoretic concepts, information theoretic principles, and the Bussgang property, methods of single channel filtering and source separation of multipath mixtures are merged into a general FIR matrix framework. Techniques developed for equalization may be applied to source separation and vice versa. Potential applications of these results lie in neural networks with feedforward memory connections, wideband array processing, and in problems with a multiinput, multioutput network having channels between each source and sensor, such as source separation. Particular applications of FIR polynomial matrix alg...
Multiobjective output feedback control via LMI
 in Proc. Amer. Contr. Conf
, 1997
"... The problem of multiobjective H2=H1 optimal controller design is reviewed. There is as yet no exact solution to this problem. We present a method based on that proposed by Scherer [14]. The problem is formulated as a convex semidefinite program (SDP) using the LMI formulation of the H2 and H1 norms. ..."
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Cited by 72 (5 self)
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The problem of multiobjective H2=H1 optimal controller design is reviewed. There is as yet no exact solution to this problem. We present a method based on that proposed by Scherer [14]. The problem is formulated as a convex semidefinite program (SDP) using the LMI formulation of the H2 and H1 norms. Suboptimal solutions are computed using finite dimensional Qparametrization. The objective value of the suboptimal Q's converges to the true optimum as the dimension of Q is increased. State space representations are presented which are the analog of those given by Khargonekar and Rotea [11] for the H2 case. A simple example computed using FIR (Finite Impulse Response) Q's is presented.
Reinforcement Learning And Its Application To Control
, 1992
"... Learning control involves modifying a controller's behavior to improve its performance as measured by some predefined index of performance (IP). If control actions that improve performance as measured by the IP are known, supervised learning methods, or methods for learning from examples, can be us ..."
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Cited by 51 (2 self)
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Learning control involves modifying a controller's behavior to improve its performance as measured by some predefined index of performance (IP). If control actions that improve performance as measured by the IP are known, supervised learning methods, or methods for learning from examples, can be used to train the controller. But when such control actions are not known a priori, appropriate control behavior has to be inferred from observations of the IP. One can distinguish between two classes of methods for training controllers under such circumstances. Indirect methods involve constructing a model of the problem's IP and using the model to obtain training information for the controller. On the other hand, direct, or modelfree,...
Feedback Control RealTime Scheduling
, 2001
"... We develop Feedback Control realtime Scheduling (FCS) as a unified framework to provide Quality of Service (QoS) guarantees in unpredictable environments (such as ebusiness servers on the Internet). FCS includes four major components. First, novel scheduling architectures provide performance contro ..."
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Cited by 33 (12 self)
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We develop Feedback Control realtime Scheduling (FCS) as a unified framework to provide Quality of Service (QoS) guarantees in unpredictable environments (such as ebusiness servers on the Internet). FCS includes four major components. First, novel scheduling architectures provide performance control to a new category of QoS critical systems that cannot be addressed by traditional open loop scheduling paradigms. Second, we derive dynamic models for computing systems for the purpose of performance control. These models provide a theoretical foundation for adaptive performance control. Third, we apply established control methodology to design scheduling algorithms with proven performance guarantees, which is in contrast with existing heuristicsbased solutions relying on laborious design/tuning/testing iterations. Fourth, a set of controlbased performance specifications characterizes the efficiency, accuracy, and robustness of QoS guarantees. The
Matrixvalued NevanlinnaPick interpolation with complexity constraint: An optimization approach
 IEEE Trans. Automat. Contr
, 2003
"... Abstract—Over the last several years, a new theory of Nevanlinna–Pick interpolation with complexity constraint has been developed for scalar interpolants. In this paper we generalize this theory to the matrixvalued case, also allowing for multiple interpolation points. We parameterize a class of in ..."
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Cited by 16 (5 self)
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Abstract—Over the last several years, a new theory of Nevanlinna–Pick interpolation with complexity constraint has been developed for scalar interpolants. In this paper we generalize this theory to the matrixvalued case, also allowing for multiple interpolation points. We parameterize a class of interpolants consisting of “most interpolants ” of no higher degree than the central solution in terms of spectral zeros. This is a complete parameterization, and for each choice of interpolant we provide a convex optimization problem for determining it. This is derived in the context of duality theory of mathematical programming. To solve the convex optimization problem, we employ a homotopy continuation technique previously developed for the scalar case. These results can be applied to many classes of engineering problems, and, to illustrate this, we provide some examples. In particular, we apply our method to a benchmark problem in multivariate robust control. By constructing a controller satisfying all design specifications but having only half the McMillan degree of conventional controllers, we demonstrate the advantage of the proposed method. Index Terms—Complexity constraint, control, matrixvalued Nevanlinna–Pick interpolation, optimization, spectral
Impedance Control of a Teleoperated Mini Excavator
 In Proc. of the 8th IEEE International Conference on Advanced Robotics (ICAR
, 1997
"... A positionbased impedance controller for excavatortype manipulators has been developed in our laboratory. This paper describes the proposed impedance controller and presents supporting experimental results. First, the problem of impedance control for a single hydraulic actuator is addressed and a ..."
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Cited by 15 (2 self)
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A positionbased impedance controller for excavatortype manipulators has been developed in our laboratory. This paper describes the proposed impedance controller and presents supporting experimental results. First, the problem of impedance control for a single hydraulic actuator is addressed and a method is presented for stability analysis. Steadystate position and force tracking of the closed loop system is also studied. Then, the desired impedance of the endeffector (bucket of the excavator) is mapped onto the hydraulic cylinders using the arm Jacobian and accurate estimates of the arm inertial and gravity terms. A nonconservative method is presented for predicting stability of the multivariable closed loop system. Experiments with an instrumented mini excavator (for the single cylinder case) show that the designed impedance controller has a good performance. Keywords: impedance control, hydraulic excavator, contact experiments. 1. INTRODUCTION The mini excavator is a heavydu...
Robust synthesis for masterslave synchronization of Lur’e systems
 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMSI
, 1999
"... In this paper a method for robust synthesis of full staticstate error feedback and dynamicoutput error feedback for master–slave synchronization of Lur’e systems is presented. Parameter mismatch between the systems is considered in the synchronization schemes. Sufficient conditions for uniform sy ..."
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Cited by 12 (6 self)
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In this paper a method for robust synthesis of full staticstate error feedback and dynamicoutput error feedback for master–slave synchronization of Lur’e systems is presented. Parameter mismatch between the systems is considered in the synchronization schemes. Sufficient conditions for uniform synchronization with a bound on the synchronization error are derived, based on a quadratic Lyapunov function. The matrix inequalities from the case without parameter mismatch between the Lur’e systems remain preserved, but an additional robustness criterion must be taken into account. The robustness criterion is based on an uncertainty relation between the synchronization error bound and the parameter mismatch. The robust synthesis method is illustrated on Chua’s circuit with the double scroll. One observes that it is possible to synchronize the master–slave systems up to a relatively small error bound, even in the case of different qualitative behavior between the master and the uncontrolled slave system, such as limit cycles and stable equilibria.
Robust multivariable estimation of the relevant information coming from a wheel speed sensor and an accelerometer embedded in a car under performance tests
 SENSORS
, 2005
"... In the present paper, in order to estimate the response of both a wheel speed sensor and an accelerometer placed in a car under performance tests, robust and optimal multivariable estimation techniques are used. In this case, the disturbances and noises corrupting the relevant information coming fro ..."
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Cited by 11 (5 self)
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In the present paper, in order to estimate the response of both a wheel speed sensor and an accelerometer placed in a car under performance tests, robust and optimal multivariable estimation techniques are used. In this case, the disturbances and noises corrupting the relevant information coming from the sensors’ outputs are so dangerous that their negative influence on the electrical systems impoverish the general performance of the car. In short, the solution to this problem is a safety related problem that deserves our full attention. Therefore, in order to diminish the negative effects of the disturbances and noises on the car’s electrical and electromechanical systems, an optimum observer is used. The experimental results show a satisfactory improvement in the signaltonoise ratio of the relevant signals and demonstrate the importance of the fusion of several intelligent sensor design techniques when designing the intelligent sensors that today’s cars need.
Multivariable Continuoustime Generalised Predictive Control: A Statespace Approach
, 1996
"... The Multivariable Continuoustime Generalised Predictive Controller (CGPC) is recast in a statespace form and shown to include Generalised Minimum Variance (GMV) and an new algorithm, Predictive GMV (PGMV) as special cases. Comparisons are drawn with the exact linearisation methods of nonlinear con ..."
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Cited by 10 (9 self)
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The Multivariable Continuoustime Generalised Predictive Controller (CGPC) is recast in a statespace form and shown to include Generalised Minimum Variance (GMV) and an new algorithm, Predictive GMV (PGMV) as special cases. Comparisons are drawn with the exact linearisation methods of nonlinear control and it is noted that the statespace approach extends readily to the nonlinear case. The resulting state space design algorithms are simpler than the corresponding transfer function based versions and have been realised as a Matlab toolbox. Keywords Predictive control, multivariable control, minimumvariance control. Multivariable Continuoustime Generalised Predictive Control: A Statespace Approach Version of 18th January 1996 Symbol Meaning SISO Single input  single output MIMO Multi input  multi output GMV Generalised minimum variance (control) IMC Internal model control PGMV Predictive generalised minimum variance (control) GPC Generalised predictive control CGPC Continuous...
The Rational Complementarity Problem
 Eindhoven University of Technology, Dept
, 1998
"... An extension of the linear complementarity problem (LCP) of mathematical programming is the socalled rational complementarity problem (RCP). This problem occurs if complementarity conditions are imposed on input and output variables of linear dynamical input /state/output systems. The resulting dyn ..."
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Cited by 9 (9 self)
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An extension of the linear complementarity problem (LCP) of mathematical programming is the socalled rational complementarity problem (RCP). This problem occurs if complementarity conditions are imposed on input and output variables of linear dynamical input /state/output systems. The resulting dynamical systems are called linear complementarity systems. Since the RCP is crucial both in issues concerning existence and uniqueness of solutions to complementarity systems and in time simulation of complementarity systems, it is worthwhile to consider existence and uniqueness questions of solutions to the RCP. In this paper necessary and sufficient conditions are presented guaranteeing existence and uniqueness of solutions to the RCP in terms of corresponding LCPs. Using these results and proving that the corresponding LCPs have certain properties, we can show uniqueness and existence of solutions to linear mechanical systems with unilateral constraints, electrical networks with diodes, an...