Kazunobu Yoshida

Stabilizing control for a single pendulum by moving the center of gravity. An investigation by numerical experiment

For a single pendulum having controllable rod length, a variable structure system, a stabilizing control law that damps the swing has been developed using Lyapunovs method. In deriving the law, the nonlinearities of the system are considered outright. The control system has a structure where the rod length is changed according to /spl theta/ and /spl theta//spl dot/ (/spl theta/ represents the rod angle) and uses the Coriolis force favorably.

A simple LP formulation of the continuous-time positive invariance condition and its application to the constrained regulator problem

A system is said to be positively invariant with respect to a set S if each trajectory starting from S stays in S. A novel, brief proof of the algebraic positive invariance (PI) condition is given using the discussion in the dual space. A linear continuous-time time-invariant system with the initial state set being a convex polytope is considered. It is shown that the conventional PI condition has a lot of redundancy in general. The authors derive a reduced-order LP without redundancy and apply this result to solving the linear constrained regulator problem. An algorithm for computing an optimal feedback gain is proposed using an explicit LP condition of a feedback gain satisfying the design criteria.

An Optimal Design of Constrained Linear Control Systems Using the Set of Admissible Gains

Abstract In the design problem of linear control systems with input and state constraints, a feedback gain is admissible if all the constraints are satisfied. This paper presents a new design method for obtaining a suboptimal linear admissible control law using a criterion for admissible gain when the set of initial states is given by a convex polyhedron. A function of gain on the constrained conditions, α( f ), is defined so that a. stable gain f is admissible α( f )≤1. An effective method for computing α( f ) by means of an LP algorithm is proposed, which is based on the method of constructing the maximal set of admissihle initial states in the dual space.

An approach to higher damping capacity: a comparison of material damping with computer-controlled damping

Abstract An approach to higher damping by positively utilizing computer-aided control techniques has been investigated by comparing the relative magnitudes of active (computer-controlled) damping and material damping. The active damping effect increases the damping capacity of a brass beam vibration system from δif=0.012 (logarithmic decrement value under free vibration) to δimax=0.3248 (total maximum damping) and this value of δimax amounts to about 4.5 times the maximum damping observed in the ferromagnetic high damping metal SIA.