Time-of-Flight Optical Sensor Multiplexing for Eye Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LIDAR systems for autonomous vehicles face limitations in maximum illumination power due to eye safety regulations, which restrict their ability to reliably detect far-away objects across varying environmental conditions such as rain, fog, darkness, and bright light.
Innovation Solution
A time-of-flight (TOF) optical sensor system with a controller and a sensing array, where the number of readout TOF modules is less than the number of sensing cells, allowing for efficient measurement and determination of object reflections by triggering connections between sensing cells and readout modules, enabling improved detection capabilities while maintaining eye safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the illumination power of LIDAR systems is increased to improve detection of far-away objects, then the detection range and reliability are improved, but the eye safety regulations are violated causing potential damage to the human eye
Solution Approach 1:
The patent implements dynamic adjustment of the illumination power based on detected objects and environmental conditions. The system continuously monitors the surrounding environment and adapts the light emission intensity in real-time, using higher power only when necessary for distant object detection and lower power for closer objects, thus maintaining eye safety while improving detection reliability
Solution Approach 2:
The system changes the illumination power parameter dynamically based on distance measurements and environmental conditions. By adjusting the power level according to the specific detection scenario, the system optimizes detection capability while preventing harmful effects to human eyes
2Device complexity
If the number of readout TOF modules is reduced to decrease device complexity, then the manufacturing cost and system complexity are reduced, but the measurement speed and data acquisition rate may be limited
Solution Approach 1:
The patent implements periodic sampling of sensing cells, where each readout TOF module sequentially serves multiple sensing cells over time. The controller systematically cycles through different sensing cell connections, enabling comprehensive data acquisition with fewer readout modules while maintaining measurement throughput
Solution Approach 2:
The sensing array is divided into multiple groups that are sequentially connected to the readout TOF modules. This segmentation allows the system to process data from all sensing cells using fewer readout modules by time-multiplexing the connections, thus reducing device complexity while preserving measurement capability
3Object-affected harmful factors
If the illumination power is limited to comply with eye safety regulations, then the eye safety is maintained, but the detection capability for far-away objects in varying environmental conditions is reduced
Solution Approach 1:
The system dynamically adjusts illumination power based on real-time environmental assessment. When detecting distant objects in challenging conditions (rain, fog, darkness), the system temporarily increases power within safety limits, while using lower power in favorable conditions, thus optimizing detection capability while maintaining eye safety
Solution Approach 2:
The system uses feedback from environmental sensing and object detection to continuously optimize illumination power. By monitoring detection quality and environmental conditions, the system adjusts power levels to achieve the minimum necessary illumination for reliable detection while staying within eye safety parameters
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 enhances the performance of LIDAR systems by enabling reliable detection of objects in diverse conditions without exceeding eye safety limits, improving the accuracy and range of object detection.
Implementation Method 1
time-of-flight (TOF) optical sensor
Implementation Method 2
measuring the reflected pulses with a sensor
Data Source
AI summary
A time-of-flight (TOF) optical sensor may include a controller, a sensing array, and a readout unit. The sensing array may include a plurality of sensing cells. The readout unit may include a plurality of readout TOF modules. The number of the plurality of readout TOF modules may be less than the number of the plurality of sensing cells. The controller may be configured to trigger a connection of a first sensing cell of the plurality of sensing cells to a first readout TOF module of the plurality of readout TOF modules at a first time during a sampling period, thereby enabling the first readout TOF module to provide a first measurement of a change in output of the first sensing cell.