Rail transit train motion state high-precision sensing device and sensing method

The invention relates to a rail transit train motion state high-precision sensing device which comprises a shell, a panel, motion state monitoring sensors and a central data processor, multi-source data of the motion state monitoring sensors are fused through the central data processor, and under the condition of not depending on a rail transit ground measuring system and a vehicle-mounted signal system, information such as the running direction, the real-time speed, the displacement information, the real-time position and the acceleration of the train can be autonomously acquired. The invention also relates to a method for realizing the high-precision displacement measurement of the rail transit train, the train displacement information is acquired by adopting a radar speed measurement and laser distance measurement combined measurement method, and the high-precision displacement measurement under various rail transit conditions can be realized. The invention also relates to a method for realizing real-time