Multi-Channel LIDAR Speed Determination via Segmented Scanning
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Solution Overview
Problem
LIDAR devices in autonomous vehicles face latency issues in estimating the speed of objects due to the delay in scanning a full 360-degree azimuth, resulting in significant movement of objects during measurement intervals, especially at lower scanning rates.
Innovation Solution
Implementing a LIDAR system with multiple channels that emit light pulses in different directions with varying yaw angles, allowing for simultaneous measurement of ranges and calculation of relative speed without the need for a full rotation, thereby reducing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the LIDAR device rotates at a lower frequency to reduce latency, then the measurement delay decreases, but the productivity of the scanning system decreases
Solution Approach 1:
The patent divides the 360-degree scanning task into multiple segments by using multiple LIDAR channels, each responsible for a specific angular sector. This allows the system to obtain measurements from different directions simultaneously rather than sequentially, reducing the time required to complete a full scan while maintaining high scanning productivity.
Solution Approach 2:
The patent introduces the dimension of angular coverage by distributing LIDAR channels across different yaw angles. Instead of a single channel scanning through all 360 degrees sequentially, multiple channels cover different angular sectors simultaneously, effectively adding a spatial dimension to the measurement process and reducing temporal latency.
2Device complexity
If the LIDAR device uses a single channel scanning through 360 degrees, then the device complexity is low, but the measurement precision for speed estimation deteriorates due to full rotation delay
Solution Approach 1:
The patent segments the scanning function across multiple channels, each measuring distance to objects in different angular sectors. This segmentation allows simultaneous measurements at different angles, enabling speed estimation without waiting for a complete 360-degree rotation, thus improving measurement precision while maintaining manageable device complexity.
Solution Approach 2:
The patent merges the measurements from multiple LIDAR channels to estimate object speed. By combining distance measurements from different angular sectors obtained simultaneously, the system can calculate relative speed without the full rotation delay, improving measurement precision while distributing the complexity across multiple coordinated channels.
3Productivity
If the LIDAR device emits light pulses at higher frequencies to improve measurement rate, then the productivity increases, but the latency in speed estimation increases due to full rotation requirement
Solution Approach 1:
The patent segments the 360-degree field of view among multiple LIDAR channels, allowing each channel to operate at high pulse emission rates independently. Since each channel only needs to scan a portion of the circle, they can emit pulses more frequently without increasing the overall rotation time, thus maintaining high productivity while reducing latency in speed estimation.
Solution Approach 2:
The patent uses the angular dimension to parallelize measurements. By distributing channels across different yaw angles, the system can perform high-rate pulse emission in multiple directions simultaneously, effectively decoupling the pulse rate from the rotation period and allowing high productivity without proportional increase in estimation latency.
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 enables more accurate and timely estimation of object speed by reducing latency and allowing for higher pulse rates, enhancing the efficiency of LIDAR systems in autonomous vehicles.
Implementation Method 1
A LIDAR device may be used to determine a range and direction to an object in its environment by emitting a light pulse in a particular direction toward the object and detecting a returning light pulse that corresponds to a portion of the emitted light pulse that is reflected by the object
Implementation Method 2
The range may be calculated based on a time difference between when the light pulse is emitted and when the returning light pulse is detected
Data Source
AI summary
A light detection and ranging (LIDAR) device includes a first light emitter, a second light emitter, a first light detector, and a second light detector, wherein the first light emitter is configured to emit light pulses in a first direction and the second light emitter is configured to emit light pulses in a second direction. During a scan of the LIDAR device, the first direction intersects an object at a first time and the second direction intersects the object at a second time. A relative speed of the object can be determined based on a first range to the object when the first direction intersects the object and a second range to the object when the second direction intersects the object.