VCSEL-SPAD LiDAR Ranging With Histogram-Based Power Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser emission modules struggle to efficiently control power consumption while emitting high-power lasers, leading to increased energy consumption and potential inefficiencies.
Innovation Solution
A method and device utilizing a VCSEL and SPAD configuration to emit a first laser beam followed by a second, lower-intensity beam, with power management through capacitors and switches, allowing for precise distance measurement using photon detection histograms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high-power laser beam is emitted continuously to maintain measurement precision, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic laser emission by alternating between first laser beams (higher power) and second laser beams (lower power) across multiple scan cycles. This periodic action allows the system to maintain measurement precision through histogram accumulation while reducing average power consumption, directly resolving the contradiction between continuous high-power emission and energy efficiency
Solution Approach 2:
The patent dynamically adjusts laser beam intensity by switching between two power levels based on scan cycle position and detection needs. The controller selectively emits higher-power beams when needed for precision and lower-power beams when sufficient signal has been accumulated, enabling adaptive power management that maintains measurement quality while optimizing energy usage
2Measurement precision
If a first laser beam with higher intensity is emitted to detect photons at short distances, then measurement capability for short distances is improved, but power consumption increases
Solution Approach 1:
The patent applies partial action by using higher-power first laser beams only when and where needed (at specific scan cycles and for specific distance ranges) rather than continuously. The system accumulates photon detections over multiple cycles, using the higher-power beams selectively to provide sufficient signal for short-distance measurement while avoiding unnecessary high-power emission that would waste energy
3Measurement precision
If multiple scan cycles are used to accumulate photon detections for histogram analysis, then measurement accuracy is improved, but time consumption increases
Solution Approach 1:
The patent maintains continuous useful action by accumulating photon detections across multiple scan cycles without interruption. The histogram is built continuously as photons are detected in each cycle, allowing the system to improve measurement accuracy through accumulation while minimizing idle time. The continuous accumulation process ensures that each additional scan cycle contributes immediately to improving the measurement result
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
This approach enables high-power laser emission with efficient power management, accurately measuring short distances without significant power consumption increases, maintaining a stable frame rate.
Implementation Method 1
emitting a first laser beam through a VCSEL (Vertical Cavity Surface Emitting Laser)
Implementation Method 2
identifying, in units of time bins having a specific time interval, at least one of time points at which at least one of photons is detected through a SPAD (Single Photon Avalanche Diode)
Data Source
AI summary
Disclosed is a method for a light detection and ranging (LiDAR) device to measure the distance from the LiDAR device to an object. Specifically, the method may include a LiDAR device: outputting a first laser beam through a vertical-cavity surface-emitting laser (VCSEL) in each of a plurality of scan cycles; identifying at least one time point at which at least one phone is detected through a single-photon avalanche diode (SPAD) optically corresponding to the VCSEL, in each of the plurality of scan cycles, in a time bin unit having a specific time interval; determining a histogram on the basis of the at least one time point; and measuring the distance between the object and the LiDAR device on the basis of at least a portion of the histogram.