Speed estimator based on machine vision, vehicle and estimation method

The invention provides a speed estimator based on machine vision, a vehicle and an estimation method. The speed estimator is embedded in a rearview of the vehicle, wherein the speed estimator is composed of a prism, a camera, a laser transmitter, a driving module, a speed estimation module and a communication module; the laser transmitter emits light source to irradiate to the prism, on the one hand, the laser source enters the camera after the refraction of the prism, on the other hand, the laser source irradiates to the ground through the prism, the ground image information arrives the camera after the refraction of the prism; the driving module is in signal connection with each of the laser transmitter and the camera, the shooting frequency of the camera is same as the transmitting frequency of the laser transmitter, and the camera is in signal connection with the speed estimator; the speed estimation module realizes signal communication with the vehicle ECU through the communication module; and the speed