Abstract
Recently, the positioning control using a DC servomotor is a fundamental technique which is common to many mechanisms, including data communication I/O equipment such as a serial printer, a magnetic disk memory, etc. Therefore, it is necessary to be faster and more accurate.
In order to speed up the point-to-point positioning control, it is necessary to consider the oscillatory characteristic of the positioning mechanism, and it is important to minimize the input energy for positioning.
For the former, the positioning control problem is formulated as an optimal regulator problem with conditions of resting the oscillatory load of one degree of freedom at the decided position and time, and of minimizing the input energy. It is concretely shown that, by the time-varying feedback system, a high speed positioning control can be realized, whose positioning time T is nearly equal to the natural oscillation period T0 of the mechanism,
Moreover for the latter, the natural oscillation influence on the minimum-energy positioning control characteristics was investigated, Results, arranged in ratio λ of T to T0, are as follow.
(1) Input energy P for an oscillatory load is greater than or equal to input energy P0 for a rigid load.
(2) In a comparatively slow region, such that λ>λ1≈1.43, P and maximum nondimensional current |u|max for the oscillatory load are almost equal to those for a rigid load.
(3) In a fast region, such that λ<λ1≈1.43 as λ decreases, P and |u|max for the oscillatory load increase more rapidly than those for a rigid load.
(4) Maximum distortion |x1-x3|max increases rapidly as λ decreases.
