Behind The Windshield Camera-Based Perception System For Autonomous Traffic Violation Detection

What is this patent about?

’787 is related to the field of computer-based traffic violation detection, specifically a camera-based system designed for interior vehicle placement to autonomously detect traffic violations. Existing traffic enforcement cameras are typically fixed and ineffective for lane violations, while exterior-mounted systems on municipal vehicles face regulatory and environmental challenges. Interior systems, however, struggle with windshield glare, infrared (IR) light blockage, and internal reflections, necessitating an improved solution for accurate and scalable traffic violation detection.

The underlying idea behind ’787 is to create a dual-camera system mounted inside a vehicle to automatically detect traffic violations. A context camera provides a general view of the scene, while a license plate recognition (LPR) camera captures license plates of violating vehicles. The LPR camera assembly includes features to mitigate the challenges of interior mounting, such as IR illumination for nighttime operation and specialized skirts to block unwanted light reflections.

The claims of ’787 focus on a license plate recognition (LPR) camera assembly designed for interior vehicle mounting. The assembly includes an LPR camera housing, a mount that positions the housing at an angle relative to the windshield, IR lights for illumination , and a multi-layered camera skirt. The key feature is the skirt's design, specifically the inner and outer skirts, where the length of at least one side of the inner skirt is determined based on the angle between the outer skirt and the windshield, optimizing the blocking of reflected IR light.

In practice, the LPR camera assembly is mounted inside a vehicle, such as a bus, with the camera angled towards the windshield to capture license plates of nearby vehicles. The IR lights illuminate the scene at night, and the specially designed skirts block ambient light and windshield reflections. The control unit processes the video feed, identifies license plates, and transmits violation data wirelessly.

This design differentiates itself from prior approaches by addressing the specific challenges of interior-mounted traffic enforcement systems. The angled mounting and the multi-layered skirt design, with dimensions calculated based on the windshield angle, optimize the capture of clear license plate images even with internal reflections and external glare. The synchronized IR LED pulsing further enhances image quality while managing heat, leading to a more reliable and accurate traffic violation detection system.