Kazuo Aida

Design of a PI-type state feedback optimal servo system

A method of designing a type-one optimal servo system is described. The design uses an exact model matching method with pole-zero cancellations. The initial values of the integrators are set according to the plant initial conditions at the beginning of control. This servo system is optimal in the sense that the performance index, comprising the quadratic forms of both the error vector and the deviation control vector from its steady-state, is minimized. The sensitivity to plant parameter variations can be reduced without loss of optimality for the nominal plant. Moreover, this servo system has the same robustness characteristic as typical optimal servo systems designed using different performance indices. Two numerical examples illustrate the efficiency of this servo system.

A design method of a generalized predictive control system based on parametrization of two-degree-of-freedom integral controllers

A new design method for a generalized predictive control (GPC) system based on parametrization of two-degree-of-freedom integral controllers has been proposed. The objective is to guarantee stability of the control system without depending on the design parameters and to achieve low sensitivity against the plant perturbation and the disturbance. The design procedure consists of two steps. First, we design a basic integral controller for a nominal plant using the linear quadratic Gaussian (LQG) method and parametrize a class of two-degree-of-freedom stabilizing controllers. Next, we tune the feedforward controller to incorporate the GPC method into our control structure. A numerical example is presented to show the effectiveness of the proposed method by comparing it with the conventional GPC method.

Model Predictive Control Based on the Parametrization of Integral Controllers

Abstract We propose a new design method for a model predictive control system based on the parametrization of integral controllers. The objective is to design the model predictive control system which guarantees the stability of the control system for a perturbed plant and to realize the robust tracking performance. In our design method, if a free parameter is stable, the stability of the control system is guaranteed. Control design is carried out while identifying plant uncertainty, which is unmodeled dynamics of an actual plant. A numerical example is given to illustrate the effectiveness of our proposed method.

Fundamental Studies on Radiation Thickness Gage (VII)

移動している板の厚さをある形の断面積をもつ放射線束で測定すると, 感度が板の厚さ変化のもつ空間周波数の値によって変化する。この特性はレスポンス関数で表わすことができる。この要素を含む自動制御系は, 他の要素の伝達関数も皆空間周波領域で考えて, レスポンス関数として計算すると統一的な計算を容易に行なうことができる。本研究では長方形断面, 円形断面の線束のレスポンス関数を計算し, これを含む圧延機の自動制御計の設計の例を示した。断面積をもつ線束のレスポンス関数は必ずむだ距離を伴うので制御系の安定に大きな影響がある。