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The most important task in Moscow metro is increasing safety of railway traffic. For safety purposes six track parameters are measured in Moscow Metro with help of track measurement car. Equipment mounted on this car works only in contact mode and doesn't provide modem requirements for accuracy. Also important task is measurement at high speeds, but contact technology limits speed of movement up to 25mph on rail switches. Current system can't measure in real-time mode.
For decision of these field of tasks non-contact photonic measurement system (KSIR) is constructed. The KSIR works at speeds up to 70 mph and measure seven track parameters.
The KSIR contains four subsystems: rail wear, height and track gauge measurement (BFSM); rail slump measurement (FTP); contact rail measurement (FKR); speed, level and car locating (USI).
KSIR contains five CCD matrix cameras, four line CCD cameras, five infrared stripe lasers and four spot infrared lasers.
Laser forms shape on the rail. CCD-camera acquires rail image and transfers it into the digital signal processor which produces preliminary calculation ofrail shape. Then image is transferred into the central computer to calculate values of rail characteristics.
Angles between photonic unit and rail bring distortions in images from cameras. Additional distortions are caused by short-focus optics and small distance between camera and track. This distance is limited by structure clearance. The transformation algorithms for distortions elimination are applied. It's based on surfaces spline-approximation. As a result the KSIR calculates coefficients of approximating polynomials. The calibration is performed for checking accuracy of measurement in BFSM, FTP and FKR units. Evaluation techniques of accuracy characteristics are considered.
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