METHOD FOR OPTICAL MEASUREMENTS OF CONTACT WIRE ELEVATION Russian patent published in 2002 - IPC

FIELD: electrified transport; measuring contact wire elevation from rail head. SUBSTANCE: method using video camera for optical measurements involves installation of this camera on moving vehicle provided with pantograph so that optical axis of its lens occurs on plane located along track axis perpendicular to its surface and directed towards raised pantograph with its pan pressed to contact wire making sure that pattern of pantograph pan in all its standard vertical and horizontal positions be not beyond field of vision of lens. Sets of templates of pantograph pan outline patters are prepared for different elevations of contact wire from rail head level between maximal and minimal permissible values; each outline pattern of pantograph pan is assigned respective code number corresponding to definite height from contact wire to rail head level. Pattern of pantograph pan with contact wire obtained in focal plane of lens is recorded. Matrix (grid) of separate cells is superposed on pattern obtained, brightness of each current cell is sequentially compared with that of next cell and difference in these values as well as polarities of these differences are determined; adjacent cells assigned first code number form one boundary of object outline pattern in mentioned matrix and those assigned second number form second boundary of object outline pattern. Objects whose upper and lower boundaries do not reach right- and left-hand boundaries of rectangular plane are excluded. Outline images of objects obtained in this way are alternately compared with set of templates of pantograph pan outline patterns by sequentially superposing templates onto outline patterns of objects and counting discriminated outline patterns of pan and template whose code numbers coincide; contact wire elevation is determined by code number of template showing minimal difference in these numbers. EFFECT: facilitated procedure, enhanced noise immunity. 8 dwg