Micromirror Lidar Beam Steering for Retroreflector Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lidar sensor performance is negatively impacted by retroreflectors, which cause optical crosstalk and noise due to direct reflection of light pulses, posing challenges for compact lidar systems lacking sufficient space for multiple laser channels.
Innovation Solution
A lidar system with an optical transmitter module featuring a plurality of micromirror devices that deflect light beams to avoid interaction with retroreflectors, controlled by a processor to adjust beam direction and intensity, using technologies like DMDs and MOEMS for dynamic modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple laser channels are used to mitigate retroreflector effects, then lidar performance is improved, but device complexity and space requirements increase
Solution Approach 1:
The patent combines multiple laser channels into a single physical location by using a spatial light modulator to independently modulate multiple virtual channels. This allows the system to achieve multi-channel functionality without requiring multiple separate laser sources, thereby improving lidar performance while reducing device complexity and space requirements.
Solution Approach 2:
The spatial light modulator serves multiple functions simultaneously: it acts as a beam splitter, modulator, and channel separator. By using this single component to perform multiple roles, the system achieves multi-channel capability without proportionally increasing the number of components, thus resolving the contradiction between reliability and device complexity.
2Reliability
If independent pulse driving circuits are used for each laser channel, then retroreflector mitigation is improved, but space requirements for transmitter hardware increase
Solution Approach 1:
The patent merges multiple independent pulse driving circuits into a single control system that interfaces with the spatial light modulator. This allows the system to maintain independent control capability for each virtual channel while using shared hardware resources, thereby improving retroreflector mitigation without increasing the physical space for transmitter hardware.
3Device complexity
If a single transmit/receive channel is used, then device complexity is reduced, but the ability to mitigate retroreflector effects is worsened
Solution Approach 1:
The patent introduces dynamic modulation capability to a single physical channel by using a spatial light modulator that can independently control multiple virtual channels in real-time. This allows the system to adaptively mitigate retroreflector effects through dynamic beam steering and modulation, achieving multi-channel mitigation capability without increasing the static number of physical channels.
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
Reduces the likelihood of sensor 'blinding' and improves lidar performance by minimizing light transmission towards retroreflectors, enabling effective data collection with reduced interference.
Implementation Method 1
The micromirror devices are configured to deflect the light beams
Data Source
AI summary
The present disclosure relates to multi-channel optical transmitter modules, lidar systems, and methods that involve micromirror devices. An example optical transmitter module includes at least one light-emitter device and a plurality of micromirror devices optically-coupled to the at least one light-emitter device. The at least one light-emitter device is configured to emit respective light beams toward an environment via the micromirror devices. The micromirror devices are configured to deflect the light beams. The optical transmitter module also includes a controller having at least one processor and a memory. The controller is configured to carry out operations. The operations include receiving information indicative of a retroreflector object in the environment. The operations include, based on the received information, causing at least one micromirror device of the plurality of micromirror devices to deflect at least one light beam so the at least one light beam does not interact with the retroreflector object.