The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 06, 2001
Filed:
Jan. 24, 2000
Stefan Turk, Wuppertal, DE;
K.A. Schmersal GmbH & Co., , DE;
Abstract
An apparatus for detecting the position of a moveable object along a path such as a rail or a wire. The apparatus includes an acoustic signal conductor, a signal input coupler, and a signal extractor. The acoustic signal conductor extends along the travel path and has a predetermined, uniform speed at which sound is propagated. The signal input coupler is located on the moveable object to couple a clocked acoustic signal into the acoustic signal waveguide. The signal extractor is arranged at one end of the acoustic signal waveguide and is connected to an evaluation unit for determining the propagation-time of the sound signal from a position at which the sound signal is coupled to the signal extractor to accordingly generate a signal representative of the instantaneous position of the moveable object on the travel path. A sensor on the acoustic signal conductor is actuated by being passed over by the moveable object. The sensor is disposed a predetermined distance from the middle of the acoustic signal conductor and is coupled to the evaluation unit. The evaluation unit compensates errors of calibration points along the travel path by using an error polynomial with coefficients derived from errors. The errors are assigned to a specific distance on the travel path by evaluating the pulse emitted by the sensor assigned to the distance upon being passed over by the moveable object.