Bathymetry LiDAR Multi-Channel Synchronous Acquisition System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LiDAR systems face challenges in achieving high sampling rate and precision data acquisition and storage, especially in bathymetry applications, due to high scanning speeds, strong water surface reflections, and the inability to adjust Photomultiplier Tube (PMT) gain in real-time, leading to incomplete data acquisition and signal saturation.
Innovation Solution
A lightweight, multi-channel high sampling rate real-time synchronous acquisition and storage system utilizing an FPGA acquisition carrier board, a ZYNQ storage daughter board, and upper computer conversion software, which includes high-speed ADC chips, a clock chip, and a self-designed communication protocol to manage data acquisition, PMT gating, and adaptive PMT gain adjustment, ensuring high-bandwidth data storage and transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high sampling rate data acquisition is implemented to capture fast scanning and platform movement, then acquisition rate and real-time performance are improved, but system complexity and difficulty of design increase significantly
Solution Approach 1:
The data acquisition system is divided into multiple independent channels, each capable of simultaneous high-speed acquisition. The FPGA-based system segments the acquisition task across multiple parallel channels, allowing each channel to operate independently at high sampling rates without overwhelming system complexity
Solution Approach 2:
The patent replaces traditional mechanical/signal-processing approaches with FPGA-based digital signal processing and ADC technology. This substitution enables high sampling rates to be achieved through electronic means rather than mechanical synchronization, reducing system complexity while maintaining high acquisition rates
2Adaptability or versatility
If multi-channel parallel signal acquisition is implemented to cover large and small fields simultaneously, then measurement coverage and real-time capability are improved, but synchronization precision and data integrity become more difficult to maintain
Solution Approach 1:
Multiple acquisition channels are merged into a unified FPGA-based processing system that handles all channels simultaneously. The FPGA integrates timing control, data acquisition, and synchronization across all channels in a single digital processing platform, ensuring precise synchronization while maintaining multi-channel coverage
Solution Approach 2:
The system implements real-time feedback mechanisms where the FPGA monitors and adjusts timing across channels based on actual acquisition conditions. This feedback control ensures synchronization precision is maintained even as the system adapts to different measurement scenarios and channel configurations
3Measurement precision
If laser energy is increased to detect deeper water bottom, then detection depth is improved, but water surface reflection becomes stronger causing signal saturation
Solution Approach 1:
The system performs preliminary actions by pre-configuring multiple acquisition channels with different aperture settings and pre-adjusting PMT gain parameters before measurement. This allows the system to be prepared with multiple detection configurations in advance, enabling selective optimization for depth versus surface reflection conditions
Solution Approach 2:
The patent implements dynamic adjustment of PMT gain parameters and gating signal timing during the measurement process. The system can adaptively change detection parameters in real-time based on water depth conditions, allowing optimization for deep water detection while avoiding surface reflection saturation through dynamic parameter modification
4Measurement precision
If PMT gain is adjusted in real-time to detect weaker echo signals from deep water, then detection capability for deep water is improved, but system complexity and control difficulty increase
Solution Approach 1:
The system implements feedback control where the FPGA monitors signal strength from each channel and automatically adjusts PMT gain parameters based on detected signal levels. This closed-loop feedback mechanism enables real-time adaptation to deep water conditions without requiring complex manual control, as the system self-regulates based on actual signal quality
Solution Approach 2:
The acquisition system performs self-service by automatically adjusting its own parameters based on real-time signal conditions. The FPGA-based control enables the system to self-optimize PMT gain and gating parameters without external intervention, reducing control complexity while maintaining high detection capability for weak deep water echoes
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 system achieves high-precision, real-time acquisition and storage of bathymetry data with low synchronization error, preventing signal saturation and ensuring complete data integrity, even in deep water environments, while being portable and energy-efficient.
Implementation Method 1
two high sampling rate ADC chips selected from AD9208 chips of ADI Company... configured for implementing data acquisition and analog-to-digital conversion of the external analog signal
Implementation Method 2
a normally off type PMT... configured for acquiring a large field deep water channel signal from a normally off type PMT
Implementation Method 3
The gating signal is applied to control a normally off type PMT to avoid the strong reflection of the water surface to acquire a water bottom signal clearly
Implementation Method 4
LiDAR has widely been applied in topographic mapping... water bottom terrestrial data of a target area is measured
Data Source
AI summary
The present disclosure relates to a lightweight and small bathymetry LiDAR multi-channel high sampling rate high-precision real-time synchronous acquisition and storage system, which adopts an ADC+FPGA+ZYNQ architecture to implement four-channel high-rate real-time synchronous parallel sampling, has synchronization error less than 300 ps, sampling rate s as high as 2 GSPS, and sampling precision as high as 14 bits, and comprises an FPGA system acquisition carrier board unit for implementing laser radar echo data acquisition and storage, PMT controlling, data maximum value feedback, peripheral interface design and storage control; a storage daughter board unit for implementing storage of echo data and export of 100 Mbps Ethernet, and an upper computer data conversion software for implementing conversion of original echo data files into decimal or hexadecimal csv files. The system has multi-channel parallel acquisition, high sampling rate and precision, strong real-time performance and functional applicability, and light weight and portability for bathymetry LiDAR.