Dual MEMS Mirror LIDAR Sensor for Long-Range Scanning
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Solution Overview
Problem
Conventional LIDAR sensors with MEMS mirrors have a limited field of view due to the restricted angular amplitude of mirror oscillation, which restricts their ability to perform long-distance scanning beyond 150 meters, especially in applications like the automotive sector where extended range is necessary.
Innovation Solution
The use of two reflective surfaces oscillating about parallel rotation axes, where the first surface deflects a light beam into the environment with a greater maximum deflection angle than the second surface, which guides received light onto a photodetector, allowing for a larger field of view and improved signal-to-noise ratio by reducing background light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single MEMS mirror is used for lateral scanning, then the device complexity is low, but the field of view is limited due to restricted angular amplitude of mirror oscillation
Solution Approach 1:
The patent divides the scanning function into two separate MEMS mirrors: a first MEMS mirror for deflecting the light beam in the emission path, and a second MEMS mirror for guiding received light in the reception path. This segmentation allows each mirror to be optimized independently, with the first mirror having a larger oscillation amplitude for wider field of view and the second mirror having a smaller amplitude for better angular resolution, thereby resolving the contradiction between device complexity and field of view.
2Area of moving object
If the maximum angular amplitude of the MEMS mirror is increased to widen the field of view, then the field of view is improved, but the angular resolution for lateral scanning deteriorates
Solution Approach 1:
The patent segments the scanning function into two mirrors with different oscillation amplitudes. The first MEMS mirror in the emission path has a larger maximum angular amplitude to achieve a wider field of view, while the second MEMS mirror in the reception path has a smaller oscillation amplitude to maintain high angular resolution when guiding light onto the photodetector. This segmentation allows simultaneous optimization of field of view and angular resolution.
3Area of moving object
If a single MEMS mirror with large oscillation amplitude is used, then the field of view is wide, but long-distance LIDAR capability beyond 150 meters is not achieved
Solution Approach 1:
The patent uses two separate MEMS mirrors to resolve the contradiction between wide field of view and long-distance capability. The first mirror with large oscillation amplitude provides wide field of view for detecting targets at various distances, while the second mirror with smaller amplitude ensures precise light guidance and high signal-to-noise ratio for long-distance detection beyond 150 meters, thereby achieving both wide coverage and reliable long-range performance.
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 LIDAR sensors to achieve long-distance scanning capabilities up to 150 meters and beyond, enhancing their effectiveness in applications like vehicle environment detection even in daylight conditions by increasing the signal-to-noise ratio and allowing for higher resolution and sensitivity.
Implementation Method 1
a first reflective surface, which is configured to oscillate about a first rotation axis in order to deflect a light beam into an environment of the LIDAR sensor
Implementation Method 2
a second reflective surface, which is configured to oscillate about a second rotation axis in order to guide light received from the environment of the LIDAR sensor onto a photodetector
Implementation Method 3
guide light received from the environment of the LIDAR sensor onto a photodetector of the LIDAR sensor
Data Source
AI summary
A light detection and ranging (LIDAR) sensor includes a first reflective surface configured to oscillate about a first rotation axis to deflect a light beam into an environment; and a second reflective surface configured to oscillate about a second rotation axis to guide light received from the environment onto a photodetector of the LIDAR sensor. The first rotation axis and the second rotation axis extend parallel to one another. The LIDAR sensor also includes a control circuit configured to drive the first reflective surface to oscillate with a first maximum deflection angle about the first rotation axis, and to drive the second reflective surface to oscillate with a second maximum deflection angle about the second rotation axis, the first maximum deflection angle being greater than the second maximum deflection angle, and an area of the first reflective surface is less than an area of the second reflective surface.