LIDAR Pulse Timing Jitter for Crosstalk-Resistant Ranging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LIDAR systems face issues with crosstalk and range aliasing due to external pulsed light sources, which degrade the accuracy of ranging operations.
Innovation Solution
Implementing per-shot jitter in the interval between successive emitter pulses, synchronized with detector operations, to reduce crosstalk and range aliasing effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If regular pulsed light emission is used for LIDAR ranging, then ranging operations can be performed, but crosstalk from external pulsed light sources and range aliasing occur, degrading measurement precision
Solution Approach 1:
The patent applies dynamic jitter to the pulse emission timing, where the interval between successive pulses varies randomly according to a probability distribution. This dynamic timing variation prevents external pulsed light sources from consistently interfering at the same detection window, thereby reducing crosstalk and range aliasing while maintaining ranging accuracy
Solution Approach 2:
The patent changes the temporal parameter of pulse emission by introducing random jitter to the pulse interval. The pulse interval is no longer fixed but varies within a range defined by a probability distribution, which transforms the static timing pattern into a dynamic one that resists predictable interference from external light sources
2Measurement precision
If per-shot jitter is applied to vary pulse intervals, then crosstalk and range aliasing are reduced, but system complexity increases due to synchronized detector operation requirements
Solution Approach 1:
The patent implements a feedback mechanism where the actual pulse emission times (including jitter variations) are recorded and used to adjust the detector's measurement windows. The detector synchronizes its operation by receiving feedback about the jittered pulse timing, allowing it to accurately associate received photons with their corresponding emitted pulses despite the variable intervals
Solution Approach 2:
The patent introduces a timing controller as an intermediary component that coordinates between the pulsed light emitter and the detector. This mediator manages the jitter application to the pulse intervals and simultaneously synchronizes the detector's measurement windows, simplifying the overall system architecture while enabling jitter-based interference reduction
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
Improves the accuracy of ranging operations by minimizing the impact of external pulsed light sources, enhancing the precision of distance measurements.
Implementation Method 1
LIDAR systems measure distance to a target by illuminating the target with a pulsed laser light and measuring the reflected pulses with a sensor. Time-of-flight measurements can then be used to make a digital three-dimensional (3D) representation of the target.
Implementation Method 2
The light sensing module has at least one light sensor channel to receive light and is configured to generate, responsive to the trigger pulse, a histogram of received light intensity as a function of time for a sequence of time bins.
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A LIDAR system having light emitters and light detectors can apply per-shot jitter to create variation in the interval between successive emitter pulses. Operation of the detectors can be synchronized with operation of the emitters so that a consistent time of flight measurement corresponds to a consistent distance. Application of per-shot jitter can reduce the effect of crosstalk from other sources of pulsed light and can also reduce range aliasing effects.