Polygon Mirror Prism LIDAR Scanning Mechanism
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Solution Overview
Problem
Current LIDAR sensors for autonomous driving vehicles face challenges in quickly and effectively scanning their surroundings to capture detailed information of objects, which is crucial for navigation and map generation.
Innovation Solution
A two-dimensional scanning system utilizing a polygonal-shaped mirror rotated in a first plane and a prism rotated in a second plane, with a single optic path for emitting and receiving laser beams, allowing for a wider scanning angle and efficient data capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a traditional LIDAR scanning system is used, then the structure is simpler, but the scanning speed and coverage area are insufficient for effective autonomous driving detection
Solution Approach 1:
The patent introduces a two-dimensional scanning mechanism by combining a polygonal mirror for horizontal scanning with a rotating prism for vertical scanning. This adds a second dimension to the scanning system, enabling comprehensive 360-degree environmental detection while maintaining rapid scanning speeds necessary for autonomous driving applications
2Area of stationary object
If a single optic path is used for emitting and receiving laser beams, then the system is more compact, but the scanning angle coverage is limited
Solution Approach 1:
The single optic path is designed to serve multiple functions: it emits laser beams toward targets, receives reflected beams, and directs them to detectors. The polygonal mirror and rotating prism within this single path work together to achieve 360-degree horizontal and vertical coverage, making the compact optic path multi-functional rather than limited
3Productivity
If rapid scanning is performed to capture surrounding information quickly, then the detection speed improves, but the measurement precision may be compromised
Solution Approach 1:
The patent employs continuous rotation of the polygonal mirror and rotating prism to maintain uninterrupted laser scanning across the environment. This continuous action ensures that multiple laser beams are emitted and received without interruption, capturing comprehensive environmental information rapidly while maintaining precision through consistent, uninterrupted measurement cycles
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
This configuration enables rapid and comprehensive scanning of objects, enhancing the accuracy and efficiency of LIDAR systems in detecting and mapping the environment for autonomous vehicle navigation.
Implementation Method 1
positioning a polygonal mirror to receive the laser beam from the laser emitter. The polygonal mirror can have a plurality of reflective surfaces and can be configured to rotate in a first rotational direction to reflect the laser beams into a first set of plurality of laser beams in a first plurality of directions
Implementation Method 2
positioning a prism to receive at least a portion of the first set of laser beams. The prism can be configured to divert the first set of laser beams into a second set of plurality of laser beams in a second plurality of directions in a second plane, so that the second set of laser beams scan a target object in a wider angle
Implementation Method 3
An optical sensor can be configured to receive a third set of laser beams reflected from the target object
Data Source
AI summary
A two dimensional (2D) LIDAR scanning system that uses a combination of a rotating polygonal mirror and a rotatable prism to scan an area of an object. The polygonal mirror and prism are rotated in combination to generate a scanning pattern. A pulsed laser is directed to the polygonal mirror and the prism is held in a fixed position. The polygonal mirror is then incremented a plurality of times to generate a scan line of LIDAR data. The prism is then incremented and a next scan line, e.g., up or down from the first scan line, is generated. An avalanche photodiode (APD) can read the reflections of objects for each scan point. Object reflections can be directed to the APD using either a polarizing beam splitter with a quarter wave plate, or a 50-50 beam splitter.