FMCW LiDAR Multidirectional Beam Encoding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional LiDAR systems face challenges in achieving a high signal-to-noise ratio (SNR) while maintaining eye safety standards, particularly at increasing distances, due to limitations in laser power and integration time.
Innovation Solution
The solution involves a multidirectional LiDAR system that uses a tunable laser source positioned remotely to a ball lens, with light transmitted via waveguides and light couplers. This system encodes modulation frequencies onto each beam, allowing for simultaneous interrogation of multiple targets/directions, which enhances the SNR and extends the effective range without exceeding safe laser exposure levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser power is increased to improve SNR, then signal-to-noise ratio increases, but eye safety is compromised
Solution Approach 1:
The patent segments the laser beam into multiple parallel beams that illuminate different angular sectors simultaneously. By dividing the total optical power across multiple beams, each beam operates at a safe power level for eye exposure, while the combined signal from multiple beams achieves the required SNR through parallel detection channels
Solution Approach 2:
The patent transitions from single-direction measurement to multidirectional simultaneous measurement by introducing angular dimension. Multiple beams cover different angular sectors, and the system resolves returns from each sector using angle-resolved detection, thereby increasing effective SNR without increasing power per beam
2Object-affected harmful factors
If laser power is limited for safety, then eye safety is maintained, but SNR decreases at increasing distances
Solution Approach 1:
The patent merges multiple detection channels that receive light from different angular sectors into a single detection system. By combining the signals from multiple parallel measurement channels, the system achieves enhanced SNR through coherent or incoherent summation, allowing safe operation at extended ranges
Solution Approach 2:
The patent creates a multi-functional detection system where a single detector or detector array serves multiple angular sectors simultaneously. Each detection channel performs the same measurement function for its assigned sector, and the combined system provides comprehensive spatial coverage with improved SNR through parallel operation
3Device complexity
If single-direction measurement is used, then device complexity is low, but productivity is limited due to sequential scanning
Solution Approach 1:
The patent segments the measurement task into multiple parallel angular channels, each measured simultaneously by dedicated detection elements. This parallelization eliminates sequential scanning delays,大幅提高 measurement throughput while maintaining manageable system complexity through modular channel design
Solution Approach 2:
The patent enables continuous simultaneous measurement across multiple angular sectors rather than sequential scanning. All directional measurements occur in parallel during each laser sweep cycle, eliminating idle time between scans and achieving maximum productivity through uninterrupted parallel operation
4Productivity
If multidirectional simultaneous measurement is implemented, then productivity increases, but device complexity increases
Solution Approach 1:
The patent introduces intermediary optical elements such as beam splitting components, relay optics, and angular selective mirrors that facilitate parallel beam generation and collection. These intermediary components enable complex multidirectional measurement functionality while maintaining relatively simple overall system architecture through modular optical design
Solution Approach 2:
The patent employs universal detection components that can process signals from multiple angular channels through a single detection array or processor. This multi-functional approach allows the same hardware to handle multiple measurement tasks simultaneously, increasing productivity without proportionally increasing device complexity
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 significantly increases the signal-to-noise ratio at laser powers below acceptable safety thresholds, enabling LiDAR devices to effectively detect objects at greater distances with improved reliability and safety.
Implementation Method 1
light is transmitted to the ball lens using waveguides with light couplers
Implementation Method 2
A tunable laser source is positioned remotely to a ball lens, and the light is transmitted to the ball lens
Implementation Method 3
A light detector collects reflected light from a target
Data Source
AI summary
Methods and systems for determining distance and velocity of one or more objects in a plurality of angular directions using an FMCW LiDAR device are described. Light from a tunable laser source is split and modulated at different frequencies that are assigned to different directions. The modulation circuit transmits swept-wavelength frequency-modulated light, which is split using waveguides with light couplers based on wavelength in some embodiments. The spectral slices are projected using a plurality of apertures onto the ball lens. After a plurality of reflected light signals are reflected by a target, a light detector may collect the reflected light signals. The reflected light signals are mixed with a local oscillator signal and converted to an electrical signal that is sent to a signal processing component. The electrical signal is used to determine the distance and velocity of the target in a plurality of angular directions in parallel.