Configurable LIDAR Histogram Memory Sharing for Distance Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LIDAR systems face challenges in providing robust distance accuracy down to a few centimeters, particularly at an economical cost, due to limitations in detector technologies like single photon avalanche diodes (SPADs) and the need for numerous memory blocks, which increase surface area requirements and create bottlenecks in data paths.
Innovation Solution
Implementing a configurable memory block system with a select circuit that allows multiple photosensors to share a memory block, using registers to store photon counts in time bins, and adjusting clock frequencies based on the number of photosensors or memory blocks to optimize data path efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of photosensors is increased, then measurement precision is improved, but device complexity increases due to requiring more memory blocks
Solution Approach 1:
Multiple photosensors are merged to share a single memory block through the select circuit. Instead of requiring one memory block per photosensor, the patent combines multiple photosensor outputs and routes them to shared memory blocks, reducing the total number of memory blocks needed in the system.
Solution Approach 2:
Memory blocks are made universal by enabling them to serve multiple photosensors. The select circuit allows any memory block to receive data from multiple different photosensors, making the memory block resource multi-functional and adaptable to different photosensor configurations.
2Measurement precision
If the number of memory blocks is increased, then measurement precision is improved, but area of stationary object increases
Solution Approach 1:
The patent merges multiple photosensor data streams into shared memory blocks, reducing the total memory block count and consequently reducing the surface area occupied on the integrated circuit. This sharing approach maintains measurement precision while minimizing area consumption.
Solution Approach 2:
The patent introduces a new dimension of resource allocation by using the select circuit to dynamically route photosensor outputs to different memory blocks. This temporal and logical multiplexing allows efficient area utilization without sacrificing the precision benefits of multiple photosensors.
3Reliability
If memory blocks are used for each photosensor, then reliability is improved, but productivity decreases due to clocking bottlenecks
Solution Approach 1:
By merging multiple photosensor inputs into shared memory blocks, the patent reduces the number of memory block clocking operations needed. This consolidation allows the data path to be clocked at higher frequencies since fewer memory blocks need to be accessed, thereby improving productivity while maintaining data integrity through the select circuit's controlled routing.
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 spatial and temporal resolution, reduces memory size, and accelerates data path clocking, improving distance accuracy and reducing costs in LIDAR systems.
Implementation Method 1
a plurality of photosensors, where each of the plurality of photosensors may be configured to detect photons from a corresponding one of the plurality of light sources
Data Source
AI summary
An optical measurement system may include a plurality of light sources and a plurality of photosensors, where the photosensors are configured to receive photons from the light sources that are reflected off objects in the surrounding environment. Photons may be stored in memory blocks corresponding to the photosensors to form histograms of the receive photons. A select circuit may be used to share memory blocks between photosensors, such that a plurality of photosensors may write to a single memory block, or a single photosensor may write to a plurality of memory blocks. Sampling clock cycles for the photosensors may be adjusted relative to the clock cycles for the memory blocks based on the select circuit output.