Lidar Test System Using Optical Fiber Delay Lines
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Solution Overview
Problem
Lidar sensors require accurate calibration, but existing methods are inconvenient in limited spaces due to the need for a maximum sensing distance of 500 m or more, making it challenging to calibrate them accurately and precisely in field or factory settings.
Innovation Solution
A lidar test system utilizing a lensed fiber collector, splitter, optical fibers of varying lengths, a switch, variable optical attenuator, and a diffuser target to simulate light pulses and intensity for calibration, allowing for precise calibration in a controlled environment without extensive space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration is performed using maximum sensing distance of 500 m or more, then measurement accuracy is improved, but space requirement increases
Solution Approach 1:
The patent introduces optical fibers as an intermediary medium to transmit light pulses between the lidar sensor and the detector array. By using optical fibers with different lengths (20m, 50m, 100m, 300m) as intermediaries, the system simulates various sensing distances without requiring physical space of 500m or more, thus resolving the contradiction between measurement accuracy and space requirement
Solution Approach 2:
The patent creates a simplified copy of the actual sensing environment by using optical fibers to replicate light transmission paths of different lengths. Instead of requiring actual physical distances of 500m+, the system uses shorter optical fiber lengths (20m-300m) that copy the essential characteristics of long-distance light propagation, enabling accurate calibration in limited space
2Measurement precision
If optical fibers of different lengths are used to simulate distances, then calibration precision in limited space is improved, but device complexity increases
Solution Approach 1:
The patent segments the calibration system into distinct modular components: multiple optical fibers of different lengths (20m, 50m, 100m, 300m), a detector array, a lensed fiber collector, and a computer. Each optical fiber segment represents a specific distance scenario, allowing independent selection and combination. This segmentation enables precise calibration for different ranges while keeping the overall system manageable through modularity
Solution Approach 2:
The patent creates a universal calibration system where a single test bench with multiple optical fiber lengths can calibrate lidar sensors for various sensing distances (20m to 300m+). The same detector array and control system serve all calibration scenarios, making the system multi-functional. This universality reduces overall complexity compared to having separate calibration systems for each distance range
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
Enables accurate and precise calibration of lidar sensors in a limited space by simulating light pulses at different distances, improving range accuracy and precision, and facilitating recalibration in lab and factory environments.
Implementation Method 1
a lensed fiber collector for receiving light pulses generated by a lidar sensor assembly
Implementation Method 2
A splitter is optically coupled with the lensed fiber collector and configured to split the light pulses received from the lensed fiber collector
Implementation Method 3
The lidar test system also includes a first optical fiber having a first length and optically coupled with the splitter for receiving one of the split light pulses. The lidar test system further includes a second optical fiber having a second length and optically coupled with the splitter for receiving one of the split light pulses, the second length being longer than the first length of the first optical fiber
Implementation Method 4
A switch is optically coupled with each of the optical fibers and configured to select light transmitted through one of the optical fibers to an optical output
Implementation Method 5
A variable optical attenuator ("VOA") is optically coupled with the optical output of the switch and configured to regulate the intensity of the light received from the switch
Implementation Method 6
a diffuser target positioned to receive light from the VOA which may be imaged by a focal plane array of the lidar assembly
Data Source
AI summary
A lidar test system includes a lensed fiber collector for receiving light pulses generated by a lidar sensor. A splitter is configured to split the light pulses received from the lensed fiber collector. A first optical fiber having a first length receives one of the split light pulses. A second optical fiber having a second length also receives one of the split light pulses. The second length of the second optical fiber is longer than the first length of the first optical fiber. A switch is configured to select light transmitted through one of the optical fibers to an optical output. A variable optical attenuator (“VOA”) is configured to regulate the intensity of the light received from the switch. The lidar test system also includes a diffuser target positioned to receive light from the VOA which may be imaged by a focal plane array of the lidar assembly.