• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.7
• /
• pp.575-582
• /
• 2004

The observer design problem is studied for a class of multi-output nonlinear systems that are not necessarily observable. Generalized nonlinear observer canonical form is introduced for multi-output nonlinear systems to design nonlinear observers. Sufficient conditions are given for a nonlinear system to be transformed by state-space change of coordinates into generalized nonlinear observer canonical form. Based on this canonical from, a sufficient condition is also given for the existence of nonlinear observers. An illustrative example is presented to show the design procedure of the proposed method.

• Journal of Mechanical Science and Technology
• /
• v.18 no.7
• /
• pp.1150-1158
• /
• 2004

In this paper, we present an adaptive observer for nonlinear systems that include unknown constant parameters and are not necessarily observable. Sufficient conditions are given for a nonlinear system to be transformed by state-space change of coordinates into an adaptive observer canonical form. Once a nonlinear system is transformed into the proposed adaptive observer canonical form, an adaptive observer can be designed under the assumption that a certain system is strictly positive real. An illustrative example is included to show the effectiveness of the proposed method.

• Proceedings of the KIEE Conference
• /
• 1998.07b
• /
• pp.429-432
• /
• 1998

This paper present a generalized observer and its existence condition. The observer can be estimated the states of system even if an external noise is added to the system's output. From a numerical example, we show that the proposed observer does not affected by a step or a sinusoidal noise.

• Journal of Institute of Control, Robotics and Systems
• /
• v.11 no.4
• /
• pp.271-278
• /
• 2005

In this paper, we present an adaptive observer for multi-output nonlinear systems that include unknown constant parameters and are not necessarily observable. Based on generalized nonlinear observer canonical form, new adaptive observer canonical form is proposed. Sufficient conditions are given for a nonlinear system to be transformed into the proposed adaptive observer canonical form. The existence of the proposed adaptive observer is given in terms of Lyapunov-like condition and SPR condition. An illustrative example is presented to show the design procedure of the proposed method.

• International Journal of Control, Automation, and Systems
• /
• v.3 no.2
• /
• pp.159-165
• /
• 2005

This paper designs observers for matrix second-order linear systems on the basis of generalized eigenstructure assignment via unified parametric approach. It is shown that the problem is closely related with a type of so-called generalized matrix second-order Sylvester matrix equations. Through establishing two general parametric solutions to this type of matrix equations, two unified complete parametric methods for the proposed observer design problem are presented. Both methods give simple complete parametric expressions for the observer gain matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the right factorization of the system, and allows eigenvalues of the error system to be set undetermined and sought via certain optimization procedures. A spring-mass system is utilized to show the effect of the proposed approaches.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.22-25
• /
• 2005

In the paper, algorithms for disturbance observers are newly presented in the time-domain. Attention is paid to observing a ramp disturbance by introducing an integral term to the output equation of a constant disturbance observer. In order to reduce the sensitivity to the measurement noise, the disturbance observer is combined with the state observer. It will be shown that the estimation dynamics can be arbitrarily chosen by assigning the eigenvalues of a characteristic equation. Also, we provide the analysis of observer behaviors subject to non-ramp-style disturbances. Finally, we propose the generalized disturbance observer that accurately estimates disturbances of higher order in time series expansion.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.45 no.1
• /
• pp.9-14
• /
• 2008

This paper presents an observer design methodology for a special class of multi input multi output(MIMO) nonlinear systems. First, we characterize the class of MIMO nonlinear systems with a triangular structure. Also, the observability matrices that plays an important role in proving the convergence of the proposed observer are generalized to MIMO systems. By using the generalized observability matrices, it is shown that under the boundedness conditions of system state and input, the proposed observer guarantees the local exponential convergence to zero of the estimation error.

• Journal of Power System Engineering
• /
• v.3 no.1
• /
• pp.55-59
• /
• 1999

Generally, T.G(Tacho-generator, Tachometer) sensor is used widely for sensing the angular velocity in rotary machine. By limitation of T.G sensor's structure, the sensed angular velocity include a periodic noise, and the noise is called "ripple" as an electrical term. To reduce the effecting of the ripple, many kinds of filters are designed and installed, but there is necessary a trade off between response time and adapted frequency band. In this paper, we propose a generalized observer to estimate an angular velocity from the output signal of T.G sensor. The generalized observer is proposed firstly for continue systems, and it is applied to DC servo motor with T.G sensor. For simulation, we measure T.G signals at 60, 400, 570 rpm respectively, and analysis those to obtain the resonance frequency of ripple by FFT method. To verify the effectiveness of the proposed algorithm, we compare the results with those of a RC low frequency band filter.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.2
• /
• pp.77-84
• /
• 1986

The design of observers for the systems with unknown and unmeasurable disturbances is treated. A generalized observer design method is proposed and existence conditions are established by combining the existing two different approaches` disturbance modelling approach by O'Reilly and algebraic approach by Kudva et. al.. The proposed approach, therefore, takes the advantages and removes the shortcomings of the existing two approaches in view points of dimensionality and existence conditions of the observer. To show the usefulness of the approach, a numerical example is given.

• International Journal of Control, Automation, and Systems
• /
• v.5 no.1
• /
• pp.93-98
• /
• 2007

A class of new observers in descriptor linear systems, proportional-derivative(PD) observers, are proposed. A parametric design approach for such observers is proposed based on a complete parametric solution to the generalized Sylvester matrix equation. The approach provides complete parameterizations for all the observer gains, gives the parametric expression for the corresponding left eigenvector matrix of the observer system matrix, realizes elimination of impulsive behaviors, and guarantees the regularity of the observer system.