Online high-precision measuring device and method for full-size parameters of wheel set of rail transit vehicle

An online high-precision measuring device for full-size parameters of a wheel set of a rail transit vehicle, comprising:

• a first laser sensor, a second laser sensor, a third laser sensor, and a polygon measuring module, wherein
• the first laser sensor is configured to measure data of an inner distance of a to-be-measured wheel set and is arranged on an inner side of a track bearing the wheel set;
• the second laser sensor is configured to measure data of a profile of a tread of the wheel set and is arranged below the track, wherein the track is provided with a slit for passage of a laser emitted by the second laser sensor;
• the third laser sensor is configured to measure data of an axle lower profile of the wheel set and is arranged on an outer side of the track;
• the polygon measuring module is butted with the track and is configured to measure a radial runout value of the tread of the wheel set;
• and
• the polygon measuring module comprises a floating probe, and the floating probe is supported by a spring to float up and down, and maintains contact with the tread of the wheel set, such that the radial runout value of the tread of the wheel set is determined.