Bong-Hwan Kwon

Eigenvalue-generalized eigenvector assignment by output feedback

This note generalizes the previous results of the closed-loop eigenstructure assignment via output feedback in linear multivariable systems. Necessary and sufficient conditions for the closed-loop eigenstructure assignment by output feedback are presented. Some known results on entire eigenstructure assignment are deduced from this result.

Optimal constant feedback with time-multiplied performance index for discrete-time linear systems

The design problem of optimal output feedback controller for discrete-time linear time-invariant systems is investigated with a class of time-multiplied quadratic performance indexes. Necessary conditions for optimality are derived. It is shown via example that the design method using such a time-multiplied quadratic performance index improves the transient response of the system.

Comments on "On some bounds in the algebraic Riccati and Lyapunov equations"

Results presented by Moil in the paper, which give some bounds for the trace and the determinant of the positive definite solution to the algebraic Riccati matrix equation, are shown to be erroneous, and suggestions to remedy these errors are made.

Optimal regulators using time-weighted quadratic performance index with prespecified closed-loop eigenvalues

Optimization of linear time-invariant systems, using a given time-weighted quadratic performance index, is investigated for the prespecified closed-loop eigenvalues. The necessary conditions have simple forms and this algorithm gives a considerable amount of computational time savings compared to the previous algorithms [1]-[2].

Optimal discrete systems using time-weighted performance index with prespecified closed-loop eigenvalues

A design problem of optimal regulators for discrete-time linear multi-input systems is investigated for the prespecified closed-loop eigenvalues. Then the design freedom, which remains after the prespecified closed-loop eigenvalues are assigned, is used to minimize a time-weighted performance index. Necessary conditions for the optimality of the controller that satisfies the prespecified closed-loop eigenvalues are derived and an algorithm for computing the optimal constant feedback gain is presented. >

Comments on ‘A note on the discrete Lyapunov and Riccati matrix equations’

A theorem presented by Tran and Sawan (1984), which gives a lower bound for the determinant of the positive definite solution of the discrete algebraic Riccati matrix equation, is shown to be erroneous.

A new controller design method for buck-type switching regulator satisfying the time domain specifications

This paper deals with a design method for the buck type switching regulator satisfying the transient and steady state performances. Necessary design considerations on the power stage are given, before designing the controller, to obtain a better closed-loop transient responses with less control effort under the constraint of the permissible switching ripple, and a feedforward compensation is also given to effectively improve the steady state performances. In the design of the controller, a PIM (proportional-integral-measurable) control method with optimized constant feedback gains is proposed to obtain better dynamic performances in the time domain without complicating the implementation of the controller. The usefulness of the proposed design method which includes the design of the controller as well as the power stage is shown by the computer simulations and experimental results.