Piezoelectric MEMS Mirror Assembly for Larger LiDAR Scan Angles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LiDAR systems suffer from limited oscillating angles due to lower torque generated by electrostatic-, piezoelectric-, or magnetic-based actuators, restricting the field of view and scanning resolution in applications like autonomous driving and high-definition map surveys.
Innovation Solution
A mirror assembly with stacked piezoelectric actuators is used, where multiple actuators are strategically placed between the rotational axis and the outer edge of the frame to enhance torque and oscillation angles, allowing for larger scanning ranges by optimizing energy transfer and actuator placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If traditional electrostatic-, piezoelectric-, or magnetic-based actuators are used to drive the mirror, then the device complexity is reduced, but the torque is lower leading to small oscillating angles
Solution Approach 1:
The actuator is divided into multiple segments including a first piezoelectric actuator and a second piezoelectric actuator arranged in different orientations. This segmentation allows each actuator to contribute to torque generation in different directions, achieving combined torque effects that exceed what a single actuator could provide, thereby resolving the contradiction between maintaining simple structure and increasing torque output.
Solution Approach 2:
The mirror assembly structure serves multiple functions: it provides mechanical support, acts as a lever arm for torque amplification, and enables rotational motion. The beam structure functions both as a structural element and as a torque transmission mechanism, making the overall device more efficient without adding external complexity.
2Length of moving object
If the oscillating angle is increased to expand the field of view, then the scanning range is improved, but the torque requirement increases which existing actuators cannot provide
Solution Approach 1:
The solution transitions from a single-axis actuator to a two-dimensional actuator arrangement with the first and second piezoelectric actuators positioned at different orientations. This dimensional change allows torque to be generated and combined from multiple directions, achieving larger oscillating angles without requiring a single high-torque actuator that would increase complexity.
3Use of energy by moving object
If a single piezoelectric actuator is used, then the device structure is simple, but the energy transfer efficiency is insufficient for large oscillation angles
Solution Approach 1:
Multiple piezoelectric actuators are merged into a coordinated system where the first and second actuators work together. Their combined action creates synergistic torque effects that improve energy transfer efficiency to the mirror, enabling large oscillation angles while maintaining reasonable device complexity through integrated design.
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 improved mirror assembly achieves larger oscillation angles and fields of view, enhancing the performance of optical sensing systems in applications such as autonomous driving and high-definition map surveys by efficiently directing optical beams over a broader range.
Implementation Method 1
a plurality of piezoelectric actuators mechanically coupled to the frame and configured to rotate the micro mirror along the rotational axis
Data Source
AI summary
Embodiments of the disclosure provide a mirror assembly for controlling optical directions in an optical sensing system. The mirror assembly may include a frame and a beam structure mechanically coupled to the frame. The beam structure may define a rotational axis. The mirror assembly may also include a micro mirror suspended by the beam structure. The mirror assembly may further include a plurality of piezoelectric actuators mechanically coupled to the frame and configured to rotate the micro mirror along the rotational axis. Each of the plurality of piezoelectric actuators may be disposed between the rotational axis and an outer edge of the frame.