DEVICE FOR DETERMINING THE LONGITUDINAL AND ANGULAR POSITIONS OF A ROTATIONALLY SYMETRICAL APPARATUS

摘要

The present invention relates to a device for determining the longitudinal and angular positions of a rotationally symmetrical apparatus (3), when guided inside an element surrounding (120) the same. The device comprises a bead (100), held in motion- transmitting contact with said apparatus, and includes an imaging optical navigation sensor (2) that measures the motion of said bead by comparing successive images (41, 42) of its outer surface (101). In a preferred embodiment, the bead is made of a paramagnetic material and the device further comprises means (123) for applying a magnetic force onto the bead to secure its contact with the apparatus (3). Additional features of the device are used to identify the insertion and withdrawal of the apparatus in the device, as they cause a displacement of the bead, therefore allowing the determination of the absolute position of the apparatus.