Takao Akiyama

T-S fuzzy model following control system for descriptor system

This paper introduces a fuzzy control design method for model following control system (MFCS) with descriptor systems. The Takagi and Sugeno (T-S) fuzzy model [1] is employed to represent a nonlinear system. In this case, a new criterion is proposed to ensure the internal states be stable.

Study of the Time-Delay System with Integral-Type

Time-delay is very often encountered in various technical systems, such as chemical processes, robotics, etc. The existence of pure time lag, regardless if it is present in the control or/and the state, may cause undesirable system transient response, or even instability. This paper discusses design of the time-delay system with integral-type. With the model following control system method, we obtain a simple input control law. The proposed methodologies are illustrated herein using example of the time-delay system. In this case, new criterion is proposed to ensure that internal states are stable.

Model Following Control System for Descriptor of Linear Time-Delay System

This paper consider the design problem of MFCS (model following control system) for a descriptor of linear time- delay system. The bounded property of internal states for control system is given and utility of this control design is guaranteed. Numerical results are given to illustrate the effectiveness of the proposed method. m m m = (4) Here, m l m R t y ∈ ) (, m l m R t r ∈ ) (, m n m R t x ∈ ) (. ) (t rm is the model input, ) (t y m is the model output and m m n n m R A × ∈ , m m l n m R B × ∈ , m m n l m R C × ∈ . Output error is given as )

A Torsion Problem of an Infinite Hollow Cylinder with Parallel External and Internal Circumferential Cracks.

This paper deals with the axisymmetric torsion problem of an infinite hollow cylinder with externally and internally circumferential cracks lying in different planes. Expressing the stress component along the crack plane as an appropriate series, the problem is reduced to the solution of an infinite system of simultaneous equations. Numerical results are presented in order to illustrate the effect of the distance between two crack planes on the stress distributions at the crack tips and stress intensity factors.

Torsion of an Infinite Hollow Cylinder with a Pair of External and Internal Circumferential Cracks

This paper deals with the axisymmetric torsion problem of an infinite hollow cylinder with a pair of external and internal circumferential cracks located on an even plane. The problem is reduced to the solution of an infinite system of simultaneous equations in which the stress on the plane is expressed as an appropriate Fourier series. Numerical results are obtained for the stresses around the crack tips and stress intensity factors.

An axisymmetric torsion problem of an elastic layer on a rigid foundation with a cylindrical hole.

A solution is presented to a doubly mixed boundary-value problem of the torsion of an elastic layer by a circular rigid punch attached to its surface. The lower face of the layer is assumed to be clamped to the rigid foundation weakened by a cylindrical hole coaxial with the punch. The problem is reduced to a solution of infinite systems of simultaneous equations in which both the displacement on the lower face of the layer and the contact stress under the punch are expressed as appropriate series. Numerical results are obtained showing the effect of the hole and the thickness of the layer on the torsional deformation and the stress field The disturbances due to the presence of the hole are also presented in curves calculated numerically, and comparisons are made with results in the absence of the hole.