Showing papers on "Observer (quantum physics) published in 1977"

Adaptive observers with exponential rate of convergence

Abstract: The problem of observing the state of an unknown, time invariant linear system from measurements of its input and output is considered. Instead of adapting the parameters in a Luenberger observer to solve the problem, as was done by earlier authors, the approach taken here proceeds from a so-called parametrized observer, which is only an alternative, equivalent representation of the Luenberger observer. However, the parametrized observer has a different structure where the state estimate is a linear function (and not a functional) of its parameters. Therefore, adapting the parameters in the parametrized observer results in a complete separation of the observer dynamics from the adaptive loop which substantially simplifies the design of suitable parameter adaptation schemes. Three such schemes are presented and proven to be globally exponentially rather than asymptotically convergent. In particular, the second and the third adaptation schemes allow the construction of adaptive observers with arbitrarily high (exponential) rates of convergence.

Real-Time Correction of Intensity Nonlinearities in Imaging Systems

Abstract: An analysis of two-dimensional imaging systems with general intensity nonlinearities is presented and several methods for real-time correction are discussed. Exact correction for measurement purposes and approximate correction for the human observer are described, and system implementation is by digital hardware, primarily using programmable read-only memories (PROM's). Calibration techniques for these systems are given, and estimates of computing time and required system complexity are made. Experimental application of these techniques is discussed.

Reduced-order observers for multivariable systems with inaccessible disturbance inputs

Abstract: The problem of observing the state vector of a multivariable system subjected to inaccessible inputs is considered. Using a polynomial-type approximation for these inputs, a set of necessary and sufficient conditions that can be readily applied to determine the existence of an observer is obtained. Computer simulation results for a third-order two-input, two-output system are included.

Observers for linear systems with arbitrary plant disturbances

Abstract: This paper shows how to choose observer parameters so that its estimation error is independent of arbitrary plant disturbances. Contrary to previous research the plant disturbances are not assumed to have any mathematical structure. Also presented are conditions under which an observer can reject plant disturbances and also have its eigenvalues arbitrarily assigned.

Sensitivity reducing observers for optimal feedback control

Abstract: This paper considers the problem of designing an observer for use in a linear quadratic optimal feedback control scheme so as to minimize the effects of small departures in the plant parameters from their nominal values.

Observable Consequences from Second-Type State Vectors of Quantum Mechanics

Abstract: Starting from a “singlet” state vector for two correlated systems we find an observable whose expectation is 3 according to quantum mechanics, while it has a maximum value of 1 if only state vectors of the first type are considered. This allows a much easier experimental check of the hitherto unobserved state vectors of the second type than suggested by Bell's inequality.

Linear function observer with possibly minimal dimension

Abstract: This technical note presents a procedure to design a linear function observer with possibly minimal dimension. The procedure is based on Gopinath's algorithm and minimal realization. A necessary and sufficient condition is also derived for the observer with specified poles.

A new look at the description and prescription of systems

Abstract: Present day status of general systems theory makes it appropriate to propose the notion of a kind of system which is able to generate the goal(s) for its own activity, a teleogenic system. This concept may apply to all levels and types of concrete systems. Some prerequisites for conceiving of such a system, and eventually founding a theory dealing with it, are outlined in this paper. The intimate relations that exist between system and observer are underscored. Any alleged property ascribed to reality is relative to the perspective of the observer. Description is facilitated through iterative modes of reflexion and the concomitant setting of a context. This permits distinguishing between a local and a global description. It is shown that the former tends to assume a causal aspect, whereas the latter is in conformity with a final aspect. It is necessary to distinguish between an unconcerned observer and a concerned observer or designer. The former only designs models to explore the system he observes, while the latter also builds the system he prescribes. The interplay between descriptive language and prescriptive language is considered. Any description is not only a representation of a reality, but, conversely, any reality exists for the observer/designer in the description made. In order to obtain a global view, one encompassing the meaning or significance of a description for the observer/designer, the assumption or prescription of goals is inevitable. According to the role goals assume, it is necessary to distinguish between goal directed, goal selecting, and goal-generating systems.

On stochastic observer estimators for continuous-time systems

Abstract: The problem of least squares state estimation for continuous linear stochastic systems having some noise-free outputs is reconsidered. It is shown that the approach of Bryson and Johansen [1] can be used to provide a simple derivation of the stochastic observer estimator in a readily implementable form.

Second-order observer for nonlinear systems from discrete noiseless measurements

Abstract: This paper presents a second-order observer which estimates the states of a nonlinear plant based on discrete deterministic measurements. The observer is obtained by applying the time-varying linear observer theory to the augmented linearized model which is obtained by replacing each quadratic term in the original system with new state variables. The gain of the observer is evaluated sequentially through a procedure similar to that in the Kalman filter. The comparison between the extended linear observer and this one is made through the computer simulation for two model systems of nonlinear type wherein one of them is an electric power system model. These simulation results indicate that the use of second-order observer leads to improved estimation performance.

Singular perturbation methods in the design of full-order observers for multivariable linear systems

Abstract: Singular perturbation methods are used to establish the conditions under which full-order observers can be designed so as to reconstruct the state vectors of multi-variable linear systems containing ‘ parasitic ’ elements, and the resulting design procedure is illustrated by designing a full-order observer for a third-order system. This procedure for the design of full-order observers is the dual of the procedure developed by Porter (1976) for the design of stabilizing state-feedback controllers for multivariable linear systems containing ‘ parasitic ’ elements.

General theory of linear hybrid control

Abstract: In this paper the suboptimality of the computer control approach in the linear quadratic problem is studied. When a digital computer controller is used, a hybrid linear control system is obtained. The parameters of this system can be chosen in different ways which all lead to suboptimal controllers. The case when a digital computer implemented observer is used was also studied and a generalization of the earlier results of Bongiorno and Youla was obtained.

Estimation of transient state of multi-machine power system by extended linear observer

Abstract: The development of extended linear observer estimating the transient state of power system has been made previously [5], using one-machine infinite bus system. In this paper, the application of this estimation technique to the multi-machine system is investigated. To get the good estimation performance defining the fast convergency of estimated value to the true value, the choice of specific combination having the least number of measurments from among a large number of combinations is most desirable. The examination is made at first, in one-machine infinite bus system, next, in multi-machine system. The results of computer simulation conclude that, at least, one measurement from each electrical and mechanical system should be adopted.

On the synthesis of an unknown input observer for a class of multi-input/output systems

Abstract: A practical design procedure of an unknown input observer for a class of multi-input/output systems is presented, the fixed poles of this observer are shown to be given by the zeros of the McMillan form.

An iterative sequential observer for estimating the transient states of a power system

Abstract: This paper presents an iterative sequential observer which enables us to estimate the transient state of power system with high accuracy. This observer attempts to reduce the effect of both the dynamic non-linearity and the measurement nonlinearity. The latter is reduced by modifying the estimates iteratively and the former by discretizing the dynamic equation at every short interval of time. Furthermore an observer gain is introduced which is easily and sequentially evaluated in a similar way as Kalman filter. Simulation results, in which the observer is applied to the system of one machine infinite bus, indicate that the state is estimated successfully even in the cases of less available measurements and there is a capability of a real-time estimation using an on-line computer.

Incorporating checks against observer error into identification keys

Abstract: Summary A method is suggested for checking for errors that may be made when an identification (or diagnostic) key is used. Such errors may arise either from tests being incorrectly used or observed, or because the specimen examined is aberrant or incomplete. The method involves constructing a check key for each endpoint of the main key. Use of the appropriate check key confirms or corrects the initial identification.

A new method of celestial navigation

Abstract: A new method of celestial navigation is presented employing the programable hand-held calculator. The technique determines the position of the observer from the "simultaneous" observation of two bodies. The only other information needed is the declination and GHA of the two bodies at their times of observation. It would be possible to determine the position of the observer, without the use of the programable hand-held calculator, with suitable tables. However, it would not have any advantage over the altitude difference method of St.-Hilaire.

Observer variations in the diagnosis of stroke. WHO collaborative study on the control of stroke in the community

Abstract: Validity and consistency of the diagnosis of stroke and its types were tested with 60 case reports including 15 diguised duplicates, drawn at random from community-based stroke registers. Seven European, 5 Japanese, and 5 other centers participated the test. The diagnosis of stroke as such (regardless of its type) seems to have been established accurately in all the 3 groups of centers; this leads to the conclusion that the incidence rates of stroke as registered in the participating centers were comparable. The diagnosis of the types of stroke was less reliable, since intra-and inter-observer bias was found in the diagnosis of the identical sample of test cases. In some European centers, the type of stroke was rarely determined, unless objective and definitive evidences were available. The Japanese centers appeared to have diagnosed the type of stroke in a relatively more uniform way between centers, however, the consistency of the diagnosis at separate times was lower. Subarachnoid hemorrhage, when diagnosed, was generally based on firmer gounds. These observations were confirmed in a small number of autopsy-verified cases. These varying diagnostic attitudes introduce false differences. Such \"softness\" of type-diagnosis must be borne in mind when comparison of type of stroke at different times or between populations is attempted.

New Equipment for the Measurement of Color‐Matching Functions

Abstract: This paper describes equipment designed to measure the color-matching functions of a human observer, together with the results obtained. Its future potentialities are discussed, as well as its limitations, accuracy, and reliability. The results obtained are in close agreement with the CIE 1964 Standard Colorimetric Observer data and will enable a statistical study of individual color-matching characteristics to be made.

Optimal observers for the state regulation of linear discrete-time plants

Abstract: The problem of designing an observer for generating suboptimal controls for a linear discrete-time regulator when some of the plant state variables are not accessible is considered. The procedure is based essentially on a minimization of the resulting increase in cost. The dependence of this performance measure on w(0), the un-measurable part of the initial plant state vector, is eliminated by averaging the performance obtained for a linearly independent set of values for w(0). The design of the optimal observer is then carried out by minimizing this average value. This procedure is also shown to ensure the stability of the overall system

Adaptive identification, observation, and control of certain linear systems

Abstract: It has been recently shown that adaptive observers may achieve an arbitrarily-fast rate of convergence if the dynamic order of the observer is sufficiently large. This paper investigates the behavior of an adaptive observer with regard to the choice of design parameters and to the magnitude of parameter, ignorance for the case where arbitrarily-fast convergence is guaranteed and the lower-order cases for which assurance of arbitrarily-fast convergence has not been given. A controller for the arbitrarily-fast placement of plant poles of stable systems is presented, also with evaluation

The interrelationship between observers and system sensitivity

Abstract: System observer theory and system sensitivity theory have developed as two distinct bodies of research literature. In this study an interrelationship between the two problem classes is considered. It is shown that the observer and the sensitivity problems are duals of each other.

Optimal observers for the state regulation of linear continuous-time plants

Abstract: The problem of designing an observer for generating suboptimal controls for a linear regulator when some of the plant state variables are not accessible is considered. The procedure is based essentially on a minimization of the resulting increase in cost. The dependence of this performance measure on ω(0), the unmeasurable part of the initial plant state vector, is eliminated by averaging the performance obtained for a linearly independent set of values for ω(0). The design of the optimal observer is then carried out by minimizing this average value. This procedure is also shown to ensure the stability of the overall system.

Some properties of statistics used for measuring observer agreement in the recording of signs

Abstract: Two indices for measuring agreement between raters axe discussed. Variances of these indices are found which enable tests to be made of whether a sample value differs from the value to be expected under a particular model of chance rating. Lastly, the issue of correcting indices of agreement for chance agreement is briefly discussed.

An algorithm for constructing minimal-order observers for linear functions of the state

Abstract: The construction of minimal-order observers for estimating vector functions of the states of linear multivariable systems is considered. By means of geometric arguments, the observer design problem is reduced to a static optimization problem in certain observer parameters. A systematic procedure for designing minimal-order stable observers is proposed that is based on a new lower bound on the required observer order, a special canonical form of the observer matrix that ensures any prescribed degree of stability, and a gradient-type function minimization algorithm. A modified procedure for designing minimal-order observers having arbitrarily specified poles is also described. The techniques developed are illustrated by means of numerical examples.

Quantum Relativity and the Cosmic Observer

Abstract: By a critique of the opposing characteristics of general relativity and quantum theory, I want to assess the possibility and form of a quantum relativity, and thereby—through the “observer problem”—to arrive at a view of the scientist as an incarnated or embodied knower, not beyond nature, but naturalized in the material universe My point of view is that of a philosopher and a physicist, and the manner is more heuristic than technical, although the technical material could be provided if necessary In my treatment of the quantum theory, I am presupposing that some form of the Copenhagen Interpretation is valid(1)

Animal track teaching

Abstract: Full-scale representations of animal tracks indicating animal activity are located on a sheet. The sheet is placed outdoors in a natural setting where the tracks may be interpreted by an observer.