METHOD TO MEASURE NON-IN-TRACK CONDITION OF HELICOPTER ROTOR BLADES AND DEVICE FOR ITS REALISATION Russian patent published in 2011 - IPC B64F5/00 

FIELD: measurement equipment.

SUBSTANCE: invention relates to optical-electronic measurement equipment and may be used to measure non-in-track condition of helicopter rotor blades. Method to measure non-in-track condition consists in the fact that reference frame of image is formed by averaging all image frames for the period of at least one rotation of rotor and is sent to shaper of frame-to-frame difference simultaneously with video signal of current frame. Maximum value of difference video signal amplitude is identified and fixed. It is used to monitor difference video signal of subsequent blade exceeding specified value from fixed amplitude, the coordinate of the first exceeding of threshold is fixed. Frame with minimum coordinate for the first exceeding of threshold is identified, and this coordinate is saved. This coordinate is averaged for the period of several rotations of rotor. Logic of basic blade searching is started. Device to measure non-in-track condition of helicopter rotor blades comprises unit of information display, optical head, comprising lens, photodetector device optically joined with it and analogue-digital converter connected to photodetector device, and unit of video signal processing, comprising comparator, shaper of frame-to-frame difference, shaper of averaged image frame, amplitude detector, unit of blade tip coordinates identification, unit of averaging of blade tip coordinates, shaper of blades image and unit of the first blade recognition.

EFFECT: improved accuracy, reliability and convenience of measurements.

9 cl, 5 dwg