VCSEL Lidar Pixel Timing for Low-Current Jam-Resistant Sensing
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Solution Overview
Problem
Existing lidar systems are costly due to the use of high-resolution detectors and mechanical or non-mechanical scanning systems, which require high electrical currents and pose challenges in generating short laser pulses for safe operation, especially in vehicles, and suffer from 'jamming' issues with periodic laser radiation.
Innovation Solution
An optoelectronic device with a pixelated transmitting device using VCSELs, where pixels are operated in different time intervals and divided into sets, allowing simultaneous illumination and reduced power density, and a coarse-resolution receiving device, minimizing the need for high-resolution detection and reducing electrical currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-resolution detectors and mechanical or non-mechanical scanning systems are used in lidar systems, then measurement precision and detection capability are improved, but device complexity and cost increase
Solution Approach 1:
The patent segments the pixel array into multiple sets that are operated in different time intervals. This temporal segmentation allows the use of simpler, coarse-resolution detectors while maintaining effective detection capability through time-multiplexed operation of pixel sets, thereby reducing device complexity without sacrificing measurement precision
Solution Approach 2:
The patent employs periodic action by operating different sets of pixels in alternating time intervals. This periodic time-multiplexed operation enables the system to achieve effective obstacle detection and distance measurement using simpler detectors, reducing the need for complex high-resolution detection systems while maintaining measurement capability
2Measurement precision
If mechanical or non-mechanical scanning systems are used, then detection capability is improved, but use of energy increases due to high electrical currents required
Solution Approach 1:
The patent divides the pixel array into multiple sets that are activated in different time intervals. This segmentation allows the system to use fewer pixels simultaneously, reducing the total electrical current required while maintaining effective detection capability through time-multiplexed operation
Solution Approach 2:
The system uses periodic activation of different pixel sets in alternating time intervals. This periodic operation reduces instantaneous power consumption and average electrical current consumption compared to continuous operation of all pixels, while maintaining detection capability
3Measurement precision
If periodic laser radiation is used in lidar systems, then detection capability is maintained, but jamming issues occur
Solution Approach 1:
The patent uses periodic action with stochastic variation - different sets of pixels are activated in different time intervals with stochastic time stamping. This creates an aperiodic pattern at the system level despite periodic operation of individual pixel sets, preventing jamming while maintaining detection capability
Solution Approach 2:
The system dynamically varies the activation patterns of pixel sets with stochastic time stamping. This dynamic, non-repetitive operation pattern prevents the periodicity that causes jamming in traditional lidar systems while maintaining effective obstacle detection and distance measurement
4Productivity
If all pixels are operated simultaneously, then productivity is improved, but power density increases which reduces eye safety
Solution Approach 1:
The patent segments the pixel array into multiple sets that are operated in different time intervals. This segmentation distributes the total power output over time, reducing instantaneous power density while maintaining effective detection coverage, thereby improving eye safety without significantly compromising productivity
Solution Approach 2:
The system employs periodic operation of different pixel sets in alternating time intervals. This time-multiplexed approach reduces the peak power density emitted at any given moment compared to simultaneous operation of all pixels, enhancing eye safety while maintaining effective obstacle detection capability
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 reduces costs, enhances eye safety, and prevents 'jamming' by stochastic time stamping, enabling operation at lower speeds and lower power density, while maintaining effective obstacle detection and distance measurement.
Implementation Method 1
each pixel of the pixel array comprises at least one laser, in particular an optoelectronic laser, such as a VCSEL (Vertical-Cavity Surface-Emitting Laser) or a VECSEL (Surface-Emitting Semiconductor Laser with an external Laser Resonator)
Implementation Method 2
a receiving device for detecting laser beams, in particular those reflected back from objects
Data Source
AI summary
An optoelectronic device, in particular for the detection of obstacles and/or for distance measurement, may include a transmitting device for emitting laser beams. The transmitting device may include an array of pixels where each pixel of the pixel array comprises at least one laser, such as an optoelectronic laser, e.g. a VCSEL. The pixels of the pixel array may be divided into several sets of pixels, and the transmitting device may be configured to operate the sets of pixels in different, successive time intervals.