The principle of rail wear measurement based on structured-light vision was analyzed. A method for dynamically measuring rail wears in vehicle-mounted was proposed. The structured-light vision sensor was installed at the bottom of the train, and the section profile of the rail was measured. Taking rail waist as measurement benchmark, the rotation matrix and translation vector between light-plane coordinate frame and designed coordinate frame were estimated by iterative closest point (ICP) algorithm, then, the rail waist profile was registered to designed profile, based on which the rail wears were calculated. Compared with previous methods, the proposed method does not need a specially vision sensor to measure the benchmark. Benchmark measurement and wear measurement are achieved with one same vision sensor. System cost is effectively reduced, and it is operable. Measurement accuracy is also guaranteed due to no need of global calibration of multi-sensor. The experimental results show that the repeatability precision of the method is high.
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