• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.48 no.4
• /
• pp.17-24
• /
• 2011

This paper presents a control scheme to cancel periodic disturbance with unknown frequency for optical disc drives. The control scheme consists of an output regulator and a frequency adaptive algorithm. Here, the frequency adaptive algorithm based on IMP plays a role in obtaining a frequency of periodic disturbance. The stability analysis of whole system and disturbance rejection performance are proven by the singular perturbation theory. The contribution of this paper are as follows. (1) There is no design constraints of the frequency range. (2) Ability for perfect disturbance rejection is preserved even with uncertain plant model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.13 no.1
• /
• pp.119-127
• /
• 1999

In this paper, a robust direct adaptive contrdler is presented in a linear time-invariant. Continuous systems with unmodeded dynamics and bounded disturbance using a rmdified control law and the adaptive law to Compensate for the drawback of ${\sigma}$-modification algorithm. The proposed algorithm is awlied to a plant with unrmdeled dynamics represented as a singular perturbation. Boundness of all signals in overall system is guaranteed with mathematical analysis. simulation results are presented the effectiveness foc the first-order plant even in the presence of unmodelled dynamics or bounded disturbance simulatneousIy.eousIy.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.5
• /
• pp.58-64
• /
• 2004

A new method to obtain approximate solutions by placing the only poles of the slow subsystem for the two-time-scale aircraft dynamic systems. The two kinds of approximate solutions are obtained by a matrix block diagonalization. One is called the uncorrected solution, and the other is called the corrected solution. The former has an error of $O({\varepsilon})$, and the latter has an error of $O({\varepsilon}^2)$. Of course, both solutions are robust enough even though they are reduced solutions. The excellence of the proposed method is illustrated by an numerical example of an aircraft longitudinal dynamics.