LIDAR System Using Neuromorphic Pixels and Sparse Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LIDAR systems face limitations due to ambient light interference, which acts as noise, and require powerful illuminators that must comply with eye safety regulations, while also needing to address issues like coexistence with other systems, adverse atmospheric conditions, and specular reflections.
Innovation Solution
A LIDAR system incorporating a transmitter with a pulsed laser illuminator and beam forming optics that outputs a sparse pattern, combined with a receiver featuring neuromorphic pixels and accumulators, which selectively deactivate and ignore subpixels not receiving light pulses, improving signal-to-noise ratio through spatial non-uniform sensitivity adaptation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If powerful illuminators are used to overcome ambient light interference, then signal-to-noise ratio is improved, but eye safety compliance becomes more difficult to achieve
Solution Approach 1:
The patent applies local quality by illuminating only specific regions of interest with laser pulses rather than uniformly illuminating the entire field of view. The transmitter selectively targets sparse patterns in the scene, concentrating illumination power where needed while leaving other areas dark. This localized illumination approach improves signal-to-noise ratio in regions of interest without requiring high overall power that would compromise eye safety compliance.
2Area of stationary object
If the entire field of view is illuminated simultaneously, then complete scene coverage is achieved, but ambient light interference increases
Solution Approach 1:
The patent segments the field of view into multiple discrete regions and illuminates them sequentially with laser pulses at different time instances. Instead of illuminating the entire field simultaneously, the system divides the scene into sparse patterns and activates different regions in time-multiplexed fashion. This segmentation approach maintains complete scene coverage over time while reducing ambient light interference in any given moment, as only a fraction of the field is illuminated at each instant.
3Measurement precision
If sparse pattern illumination is used to reduce ambient light interference, then signal-to-noise ratio improves, but complete scene coverage requires multiple illumination periods
Solution Approach 1:
The patent employs periodic action by repeatedly illuminating sparse patterns across the field of view over multiple illumination periods. The transmitter cycles through different sparse patterns in a periodic manner, ensuring that all regions of the scene are eventually illuminated. This periodic illumination strategy maintains high signal-to-noise ratio during each individual period while achieving complete scene coverage through the repetition and accumulation of measurements across multiple periods.
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 solution effectively reduces ambient light interference, enhances signal-to-noise ratio, and increases the range and accuracy of LIDAR systems by using a sparse pattern and neuromorphic pixel technology, allowing for better performance in challenging environments.
Implementation Method 1
Each subpixel may include a photodiode biased by a non-linear element
Implementation Method 2
The non-linear element may be a diode connected MOS_FET in sub-threshold region
Implementation Method 3
measuring the time in which the reflection returns from the different objects (time of flight)
Data Source
AI summary
A LIDAR system that may include a transmitter and a receiver. The LIDAR system may include a transmitter and a receiver that may include an array of neuromorphic pixels and multiple accumulators. Each neuromorphic pixel may include multiple subpixels, an analog adder and a comparator; wherein for each reception period the analog adder is configured to generate an analog adder signal by adding detection signals from subpixels that are expected to receive at least one received light pulse during the reception period; wherein for each reception period the analog adder signal is indifferent to subpixels that are not expected to receive any received light pulses during the reception period; and wherein the comparator is configured to provide pixel output signals by comparing the analog adder signal to a threshold. The multiple accumulators are configured to add multiple pixel output signals from neuromorphic pixels to provide, for each neuromorphic pixel, an accumulated signal that represents radiations sensed by the neuromorphic pixel during the multiple reception periods.