LiDAR Flight Time Detection Using Unipolar Signal Correlation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LiDAR apparatuses face challenges in accurately obtaining flight time of light in noisy environments or with small measuring signals, which affects the accuracy of depth image processing.
Innovation Solution
The LiDAR apparatus includes a light transmitter, a light receiver, and a processor that converts signals into unipolar form using high-pass filters and analog-digital converters, calculates cross-correlation functions, and adjusts signal intensity to detect flight time accurately, even in noisy conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional signal processing methods are used to measure flight time, then the measurement process is simple, but measurement precision deteriorates in noisy environments or with small measuring signals
Solution Approach 1:
The patent segments the signal processing into distinct stages: offset removal through high-pass filtering, quantization through ADC, unipolar conversion, and cross-correlation analysis. This segmentation allows each stage to specifically address different aspects of noise reduction and signal enhancement, thereby improving flight time measurement accuracy in noisy environments.
Solution Approach 2:
The patent introduces intermediate processing steps between signal reception and flight time detection. Specifically, it uses high-pass filters as intermediaries to remove offset, ADC as an intermediary to quantize signals, and unipolar conversion as an intermediary transformation. These intermediaries progressively clean and prepare the signals for accurate correlation-based measurement, reducing noise impact at each stage.
2Measurement precision
If signal intensity is increased to improve detection in noisy environments, then measurement precision improves, but use of energy increases
Solution Approach 1:
The patent extracts and removes the offset component from the signal using high-pass filtering before further processing. By taking out the harmful offset component separately, the system can work with the remaining useful signal components more efficiently, improving detection accuracy without requiring excessive signal intensity and thus reducing energy consumption.
Solution Approach 2:
The patent performs preliminary signal conditioning actions before the main measurement process. By pre-removing offset, pre-quantizing signals, and pre-converting to unipolar form, the system prepares the signals in advance for correlation analysis. This preliminary action ensures that the subsequent flight time detection can be performed accurately even with moderate signal intensity, avoiding the need for excessive energy input.
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 enhances measurement accuracy by reducing the impact of noise and ensuring accurate detection of flight time, enabling precise distance calculation and improved depth image generation.
Implementation Method 1
a photo-detector configured to obtain the first signal by converting the received laser pulse into an electrical signal
Data Source
AI summary
A light detection and ranging (LiDAR) apparatus and a method of operating the LiDAR apparatus are provided. The LiDAR apparatus includes a light transmitter configured to irradiate a laser pulse towards an object, the laser pulse being generated based on a reference signal; a light receiver configured to receive the laser pulse reflected from the object and configured to obtain a first signal from the received laser pulse; and at least one processor configured to convert the first signal and the reference signal respectively into unipolar signals and configured to detect a flight time of the laser pulse based on a correlation between the converted first signal and the converted reference signal.