MEMS-Actuated Risley Prisms for Solid-State LiDAR Steering
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Solution Overview
Problem
Existing LiDAR systems face limitations in angular range and resolution due to mechanical motor-driven Risley prisms, making them difficult to implement as solid-state steering devices.
Innovation Solution
Integration of MEMS-based angular comb drive actuators with Risley prisms to independently control the rotation of each prism, enabling a solid-state steering device for LiDAR systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If mechanical motors are used to drive Risley prisms, then the angular range and rotation speed can be achieved, but the device complexity increases and solid-state integration becomes difficult
Solution Approach 1:
The patent replaces traditional mechanical motor-driven systems with MEMS (Micro-Electro-Mechanical Systems) technology. The MEMS mirror array uses electrostatic actuation to rotate individual mirrors, eliminating the need for bulky mechanical motors while achieving the required rotation speeds and angular ranges. This substitution of mechanical systems with micro-electromechanical systems directly resolves the contradiction between achieving high rotation speed and reducing device complexity.
Solution Approach 2:
The patent changes the operating parameters by using independent control of multiple MEMS mirrors instead of a single mechanically-driven prism pair. Each mirror can be rotated to different angles independently, allowing for dynamic adjustment of scanning patterns, angular range, and resolution without the mechanical constraints of traditional motor-driven systems.
2Adaptability or versatility
If traditional mechanical motor-driven Risley prisms are used, then beam steering is achieved, but integration as solid-state devices is difficult
Solution Approach 1:
The patent replaces traditional mechanical motor-driven systems with MEMS (Micro-Electro-Mechanical Systems) technology. The MEMS mirror array uses electrostatic actuation to rotate individual mirrors, eliminating the need for bulky mechanical motors while achieving the required rotation speeds and angular ranges. This substitution of mechanical systems with micro-electromechanical systems directly resolves the contradiction between achieving high rotation speed and reducing device complexity.
Solution Approach 2:
The patent creates a multi-functional beam steering system where the MEMS mirror array can perform multiple functions: raster scanning, riskley prism-like beam steering, and adaptive optical correction. This universal platform integrates previously separate mechanical systems into a single solid-state device that can operate in multiple modes, enhancing adaptability while reducing overall system complexity.
3Measurement precision
If Risley prisms rotate at different speeds, then higher resolution scanning is achieved, but control complexity increases
Solution Approach 1:
The patent segments the beam steering function into multiple independently controllable MEMS mirrors instead of using a single mechanically-driven Risley prism pair. Each mirror can be rotated at different speeds and angles independently controlled by electronic signals, allowing for complex scanning patterns and high-resolution imaging without the mechanical coupling constraints of traditional systems. This segmentation enables precise electronic control of each mirror's rotation speed.
Solution Approach 2:
The patent implements dynamic control where the rotation speeds and angles of individual MEMS mirrors can be adjusted in real-time based on scanning requirements. This dynamic capability allows the system to optimize resolution by varying rotation speeds during different phases of the scanning cycle, while the electronic control system adapts to maintain synchronization and coordinate the mirrors' movements.
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
Enhances angular range and resolution in LiDAR scanning by allowing independent rotation of Risley prisms, facilitating higher scanning precision and efficiency.
Implementation Method 1
MEMS-based angular comb drive actuators
Implementation Method 2
At least one prism of the plurality of prisms is configured to rotate relative to at least one other prism of the plurality of prisms to refract the optical signals towards the respective different directions
Data Source
AI summary
Embodiments of the disclosure provide a transmitter containing a Risley prism-based scanning mechanism, an optical sensing system containing the same, and an optical sensing method using the same. For example, the optical sensing system includes a laser emitter configured to sequentially emit a series of optical signals. The optical sensing system further includes a plurality of prisms configured to receive the series of optical signals and sequentially direct the series of optical signals at different directions in an angle of view of the optical sensing system. At least one prism of the plurality of prisms is configured to rotate relative to at least one other prism of the plurality of prisms to refract the optical signals towards the respective different directions. The optical sensing system additionally includes a receiver configured to receive at least a portion of the series of optical signals reflected from an environment surrounding the optical sensing system.