Velocity measurement method based on stereoscopic vision

Abstract

The invention discloses a velocity measurement method based on stereoscopic vision, which comprises the following steps of: S1. acquiring the image of a static marker ahead when a carrier runs and processing the image in space dimension and time dimension according to the correlation of the image in space and time to obtain the measured value of running velocity of the carrier; and S2. measuring change rate omega of gradient Phi of the orbit of the carrier and acceleration speed ax of the carrier in running direction, establishing a process model and a measurement model which are used for estimating running velocity on the basis of the measured value of running velocity, the change rate omega and the acceleration speed ax, and estimating the running velocity of the carrier as the final result by Kalman filter algorithm according to the process model and the measurement model. The method can eliminate influence of wheel idling and slipping on the velocity measurement accuracy and realize low noise and real-time velocity measurement.

Description

technical field The invention belongs to the technical field of rail transit, in particular to a speed measurement method based on stereo vision. Background technique Speed ​​is an important data for train driving and safety control, and its accuracy and reliability determine the running quality of the train. At present, the running speed of the train is mainly measured by directly or indirectly counting the wheels, and then the speed of the train is calculated according to the circumference of the wheels and the number of revolutions of the wheels per unit time. The accuracy of this method is affected by wheel diameter wear and relative slip between wheel and rail. Although some existing compound speed measurement methods integrate some sensor data, the measurement data based on wheel count is still the main basis for speed estimation, so its accuracy is still affected by wheel diameter wear and relative slip between wheel and rail. Therefore, although the speed measurem...

AI Technical Summary

Problems solved by technology

Although some existing compound speed measurement methods have fused the data of some sensors, the measurement data based on the wheel count is still the main basis for speed estimation, so its accuracy is still affected by the wear of the wheel diameter and the relative slip between the wheel and the rail.

Therefore, although the speed measurement method based on wheel counting is simple in principle and easy to implement, its measurement accuracy is easily affected by wheel diameter changes, wheel idling, and slippage.

Moreover, the timing of idling and slipping and the resulting errors are difficult to describe mathematically, so their influence cannot be eliminated through complex mathematical processing and fusion filtering

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