Technische Universitat Munchen

Fos4x Gmbh

Thorbjörn Buck

Mathias Müller

Rolf Wojtech

Lars Hoffmann

Mathias MÜLLER

The present invention relates to a method for compensation, for example, for temperature compensation of a fiber optic measurement system designed for determining a mechanical quantity. First and second fiber Bragg gratings have a respective Bragg wavelength, wherein the fiber Bragg gratings are irradiated with primary light. After applying a mechanical quantity to the first and second fiber Bragg gratings, the Bragg wavelengths of the fiber Bragg gratings are changed by the mechanical quantity. Filtering of the first and second secondary light, said first and second secondary light is effected from the primary light and modified by the Bragg wavelength of the fiber Bragg grating depending on the mechanical quantity by use of an optical filter device follows, in such a way that the Bragg wavelength of the first fiber Bragg grating lies in the region of the rising filter gradient of the optical filter device and the Bragg wavelength of the second fiber Bragg grating lies in the region of the falling filter gradient of the optical filter device. After determining the intensities of the filtered first and second secondary light, they are compared, whereupon the mechanical quantity is determined from the intensity comparison.

Method for compensation of fiber optic measurement systems and fiber optic measurement system

A method for the adjustment of an optical measurement system comprises providing an optical measurement system, which comprises, as optical elements, a beam splitter; a first photo sensor, exposed by a first partial beam from the beam splitter; an optical filter; a second photo sensor, arranged downstream of the optical filter, exposed by a second partial beam from the beam splitter. Additionally, the angularity and relative position between multiple optical elements is designed to be adjustable. The method further comprises providing a device for generating a difference signal from the two photo sensors; providing a light source with periodically varying polarization; irradiating the light in the beam splitter, so that the two respective photo sensors are exposed by a partial beam; generating a difference signal of the output signals of the photo sensors; varying the position and/or angularity of at least one optical element, and observing the difference signal, determine the combination of angularity/position of the elements where a minimum difference signal is achieved, and configuring the angularity of the optical elements to the determined values. Further, a corresponding system is proposed.

Optical measurement system with polarization compensation, and corresponding method

A method for state monitoring of a rotor blade of a wind turbine is described. The method comprises: measuring an acceleration of the rotor blade with a first signal, wherein the acceleration is measured at a first position at a predetermined distance from the rotor blade root in at least one direction comprising a first directional component orthogonal to the axis of the rotor blade, measuring a strain of the rotor blade with a second signal, wherein the strain is measured at a second position disposed in the area of the first position to the rotor blade root, determining a first positional change at the first position on the basis of the acceleration, determining a first value corresponding to the rotor blade stiffness or to the rotor blade elasticity by means of calculation on the basis of the first positional change and the strain, and determining the rotor blade state from the first value.

Method and device for monitoring the state of rotor blades

The present invention provides a method for installing at least one sensor device within a rotor blade of a wind turbine. A first substantially planar light beam is emitted in the interior of the rotor blade. Finally, at least one second substantially planar light beam is emitted in the interior of the rotor blade, wherein the plane of the first planar light beam is oriented at a predetermined angle to the plane of the second planar light beam. Further, the planes of the first and second planar light beams are aligned on the blade flange of the rotor blade. At least one sensor device is subsequently aligned in reference to the planar light beams.

Growing community of inventors

Munich, Germany

Thorbjörn Buck