Vehicle Laser Radar Dual Emission Parts Road Mark Detection
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Solution Overview
Problem
Conventional in-vehicle radar devices face challenges in detecting road marks on a road surface, particularly discontinuous markings, due to the contraction of the irradiated area, which increases the load on the laser diode and reduces detection reliability.
Innovation Solution
A laser radar device with a second laser emission part that generates a measuring laser beam with a larger beam spread angle than the first laser emission part, allowing for more reliable detection of road marks on the road surface without increasing the number of scans per unit time, thereby reducing the load on the laser diode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of scanning per unit time and the number of irradiations per unit time are increased to scan the predetermined area on the road surface entirely, then the detection reliability of road marks is improved, but the load on the laser diode increases and its life is reduced
Solution Approach 1:
The patent divides the laser emission system into two separate emission parts: a first laser emission part for irradiating the area in front of the vehicle and a second laser emission part for irradiating the road surface. This segmentation allows each part to be optimized independently, with the second part having a larger beam spread angle specifically for road mark detection, thereby reducing the scanning frequency needed and lowering the load on the laser diode while maintaining detection reliability.
Solution Approach 2:
The patent applies different beam spread angles to different emission parts: the first laser emission part uses a smaller beam spread angle for front area irradiation, while the second laser emission part uses a larger beam spread angle for road surface irradiation. This local quality differentiation allows the road surface detection to cover a wider area with fewer scans, reducing the overall load on the laser diode while maintaining detection reliability for road marks.
2Measurement precision
If the beam divergence angle is narrowed down to contract the irradiated area and increase power density, then the detection sensitivity of continuous white lines is improved, but the detection ability of discontinuous road marks deteriorates
Solution Approach 1:
The patent segments the detection function into two separate emission parts with different beam spread angles. The second laser emission part specifically uses a larger beam spread angle to irradiate the road surface, which ensures that both continuous and discontinuous road marks are detected reliably, while the first emission part handles front area detection with optimized parameters.
Solution Approach 2:
The patent assigns different beam spread angles to different emission parts based on their specific detection requirements. The second laser emission part uses a larger beam spread angle optimized for road surface detection, ensuring that discontinuous road marks are captured within the irradiated area, while the first emission part uses a smaller beam spread angle for front area precision detection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables more reliable detection of road marks, including discontinuous markings, while reducing the load on the laser diode and improving detection performance in both the front traveling direction and on the road surface.
Implementation Method 1
causing each of plural reflective surfaces of a rotating polygonal mirror to sequentially reflect a laser beam emitted from a single laser diode
Implementation Method 2
causes the concave reflective surface of the polygonal mirror to reflect downward and converge the light emitted from the laser diode so that an area on the road surface irradiated by the laser beam irradiation contracts
Data Source
AI summary
A laser radar device mounted on a vehicle includes a first laser emission part configured to generate a measuring laser beam by using a laser beam emitted from a laser source and to illuminate a predetermined area in a front traveling direction and a second laser emission part configured to generate a measuring laser beam by using the laser beam emitted from the laser source. A beam spread angle, viewed from a side of the vehicle, of the measuring laser beam generated by the second laser emission part is larger than a beam spread angle, viewed from a side of the vehicle, of the measuring laser beam generated by the first laser emission part.