MEMS Polygon Light Steering for 360-Degree LiDAR Scanning
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Solution Overview
Problem
Existing light steering systems, such as mechanical polygon assemblies and micro-mirror arrays, face reliability, precision, and synchronization issues that degrade performance, particularly in achieving a 360-degree field of view (FOV) for LiDAR systems, leading to potential blind spots and reduced scanning resolution.
Innovation Solution
A solid-state light steering system utilizing a MEMS-based polygon assembly on a silicon substrate, comprising a polygon with facets, a support structure, and actuators, which are fabricated as a unitary structure to provide a 360-degree FOV without synchronization needs, using actuators like electrostatic or piezoelectric actuators and elastic connection structures to rotate the polygon accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical polygon assemblies are used for light steering, then a 360-degree FOV can be achieved, but reliability and precision degrade due to mechanical wear and alignment issues
Solution Approach 1:
The patent replaces the mechanical polygon assembly with a solid-state MEMS device that uses electrostatic or piezoelectric actuators to rotate a single polygon component. This eliminates mechanical wear and alignment issues while maintaining the 360-degree FOV capability, thereby improving reliability and reducing device complexity.
Solution Approach 2:
The patent integrates the polygon, support structure, and actuators into a single unitary structure fabricated on a silicon substrate. This merging of components eliminates the need for separate mechanical assemblies and reduces alignment errors, improving both reliability and precision.
2Area of stationary object
If multiple micro-mirror arrays are used to achieve 360-degree FOV, then coverage is improved, but synchronization precision deteriorates
Solution Approach 1:
The patent divides the 360-degree FOV into segments by using a single polygon with multiple facets, where each facet covers a specific angular range. This segmentation approach eliminates the need for multiple synchronized micro-mirror arrays while maintaining comprehensive coverage and precision.
Solution Approach 2:
The patent combines multiple micro-mirror functions into a single polygon assembly with multiple facets, all controlled by a single actuator system. This merging eliminates synchronization requirements between multiple independent arrays while achieving the same 360-degree coverage.
3Ease of operation
If mechanical polygon assemblies are used, then light steering capability is provided, but manufacturing precision and alignment accuracy deteriorate
Solution Approach 1:
The patent replaces mechanical alignment systems with electrostatic or piezoelectric actuators that can be precisely controlled through voltage application. This substitution improves manufacturing precision by eliminating mechanical alignment steps while maintaining light steering capability.
Solution Approach 2:
The patent uses electrostatic or piezoelectric actuators where the rotation angle can be precisely controlled by changing the voltage parameter. This allows for high manufacturing precision and alignment accuracy, as the angular position can be accurately determined and controlled through electrical parameters rather than mechanical assembly.
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 system enhances reliability and precision, avoiding alignment and balancing issues while providing a comprehensive 360-degree FOV, reducing wear and tear, and maintaining high scanning resolution by rotating a single polygon component.
Implementation Method 1
using actuators like electrostatic or piezoelectric actuators
Implementation Method 2
using actuators like electrostatic or piezoelectric actuators
Implementation Method 3
rotate the polygon around the rotation axis to reflect light emitted by a light source out of the LiDAR module or to reflect light received by the LiDAR module to a receiver
Data Source
AI summary
In one example, a Light Detection and Ranging (LiDAR) module is provided. The LiDAR module comprises a semiconductor integrated circuit comprising a micro-electromechanical system (MEMS) formed on a surface of a silicon substrate, and a controller, the MEMS comprising a polygon assembly, the polygon assembly comprising: a polygon; a support structure connected to the polygon and forming a stack with the polygon along a rotation axis; a plurality of anchors formed on the surface of the substrate; and a plurality of actuators, each actuator of the plurality of actuators being connected between the support structure and an anchor of the plurality of actuators. The controller is configured apply a voltage across each actuator of the plurality of actuators, wherein the voltage causes each actuator to exert a torque on the support structure to rotate the polygon around the rotation axis by a target rotation angle.