Real-time measurement method of vehicle speed based on video processing

Abstract

The invention discloses a method for real-time measurement of vehicle speed based on video processing, which converts objects on the road surface from the video frame coordinate system (u, v) to the road surface coordinate system (x, z): where a is the road surface coordinate system The distance between two parallel lane-dividing lines, b is the length of lane-dividing lines in the road surface coordinate system, v ∞ is the v-axis coordinate of the vanishing point in the video frame coordinate system, u left , u right are the intersection coordinates of two parallel lane-dividing lines on the road surface and the u-axis in the video frame coordinate system, v 1 , v 2 They are the v-axis coordinates at both ends of the same lane line in the video screen coordinate system; the coordinate movement distance after the same moving object in two adjacent video frames is transformed into the road surface coordinate system is divided by the time difference between two adjacent video frames Get the speed per hour of the moving object on the road. The invention utilizes the perfect existing road traffic video monitoring network in China as its original data source to implement automatic, convenient and accurate real-time measurement of vehicle speed.

Description

technical field [0001] The invention relates to the technical field of traffic management. More specifically, the present invention relates to a method for real-time measurement of vehicle speed based on video processing. Background technique [0002] The traffic management system is an effective means to control traffic congestion, and has important application prospects in many aspects such as traffic flow control, driving efficiency improvement, traffic accident risk reduction, energy saving and emission reduction. During the operation of this system, important traffic parameters such as vehicle speed and flow at each point in the road network need to be collected in real time. At present, the main means of collecting such data include induction coil detection, laser detection, radar detection and so on. The induction coil needs to be buried underground, and both construction and maintenance require excavation and reconstruction of the road surface, so the cost is high,...

AI Technical Summary

Problems solved by technology

The induction coil needs to be buried underground, and both construction and maintenance require excavation and reconstruction of the road surface, so the cost is high, and the maintenance process will block normal traffic. In addition, the service life of the induction coil is inversely proportional to the average traffic flow. In recent years, the explosive growth of highway traffic has had a huge impact on the service life of induction coils, further reducing its cost performance and product competitiveness.

Laser speed measurement has a high probability of false detection and missed detection due to low laser divergence, and laser speed measurement has a certain risk of eye injury to the drivers and passengers of the vehicle

The current popular radar speed measurement generally needs to limit the movement direction of the speed measurement object (the radar wave and the movement direction need to be less than 15 degrees) to ensure measurement accuracy. In addition, radar speed measurement is often affected by similar radio frequency bands (such as vehicle-mounted vehicles installed to avoid speed measurement radar) Radar interference equipment) or the interference of radar waves reflected from other vehicle surfaces adjacent to the test object, resulting in missed or false detections

Finally, there is a common defect in the above three speed measurement methods, that is, none of them can directly record the identity of the speed measurement object. Therefore, when the identity of the speed measurement object needs to be determined, it is necessary to install additional high-speed camera equipment to simultaneously capture the speed measurement objects one by one. , which not only significantly increases the complexity and cost of use of these two speed measurement methods, but also has a certain negative impact on their reliability

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