Method and arrangement for monitoring objects

Abstract

The present invention relates to methods and to arrangements for monitoring an object which emits a rotating or oscillating beam whose angular velocity is unknown. The time points at which the beam passes a predetermined number of measuring positions are determined. An angular velocity start value is generated and a predetermined number of object position determinations (at least two independent determinations) are made on the basis of the determined time points, the measuring positions and the start value. It is determined whether or not the position determinations can be considered to be sufficiently in agreement with one another. When agreement is considered sufficient, the start value is accepted as an approximate value, this value approximating the angular velocity of the beam with an acceptable degree of accuracy. If the position determinations are not found to be sufficiently in agreement, the start value is modified and new position determinations are made. This procedure is repeated as often as is required for the position determinations to become sufficiently in agreement with one another, wherewith the start value is accepted as a approximate value of the angular velocity. Subsequent to having obtained the approximate value of the angular velocity, a final position determination of the object can be made.