Triangular Laser Sheet Alignment for Over-Height Vehicle Detection

The patent replaces complex mechanical alignment systems with an optical self-alignment mechanism. The laser beam automatically defines the measurement plane, and the camera captures reflections within this plane without requiring precise mechanical positioning of multiple transmitters and receivers. This substitution of mechanical alignment with optical field-based alignment resolves the contradiction by maintaining detection reliability while dramatically reducing installation complexity.

The patent introduces a laser-defined measurement plane as an intermediary between the transmitter and camera. This optical intermediary creates a reference frame that automatically guides the measurement process, eliminating the need for complex mechanical positioning systems. The laser plane serves as a mediator that simplifies the interaction between components while maintaining measurement accuracy.

The patent segments the detection space into a defined laser measurement plane and separates relevant reflections (from vehicles within the plane) from irrelevant reflections (from vehicles outside the plane). By segmenting the field of view to only process reflections within the laser-defined plane, the system maintains high measurement precision while eliminating false alarms from vehicles outside the target zone.

The patent applies local quality by concentrating the optical measurement energy into a specific plane defined by the laser sheet. The camera is optimized to capture only reflections within this local plane, creating a zone of high measurement precision while automatically rejecting signals from other spatial locations. This local optimization resolves the contradiction by improving accuracy within the target plane without generating false alarms from outside the plane.

The patent creates a universal detection system where a single device combines laser projection, optical measurement plane definition, and camera-based height detection. This multi-functional device can be installed in various locations (bridge approach, overhead structures, roadside) without requiring site-specific customization of multiple separate components. The system maintains detection capability while achieving versatility across different installation sites.

The patent merges the laser transmitter and camera into a co-located system that shares a common optical reference frame. By combining these components into a single integrated unit with shared positioning, the system achieves detection capability while becoming adaptable to various site configurations. The merged design eliminates the need for separate alignment procedures for multiple components, thereby improving site installation flexibility.