Light Detecting Device Malfunction Diagnosis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing distance measuring systems for automated driving, such as those described in PTL 1, are complex and lack efficient malfunction diagnosis capabilities, particularly when increasing the number of light receiving elements to improve accuracy, leading to increased processing time and complexity.
Innovation Solution
A light detecting device with a calculation unit that generates histograms for light reception times and includes a malfunction detecting unit to diagnose issues within the calculation unit, using sampling, addition, histogram generation, and echo detection circuits, and employing test patterns to identify malfunctions across area calculation units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of light receiving elements is increased to improve distance measurement accuracy, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The light receiving element array is divided into multiple regions, with each region processed by a dedicated area calculation unit. This segmentation allows the system to handle large numbers of light receiving elements through modular processing, reducing overall system complexity while maintaining measurement precision.
Solution Approach 2:
The patent applies partial action by processing different regions with different levels of detail. Not all regions require the same processing intensity, allowing the system to optimize between accuracy and complexity by applying appropriate processing to each region.
2Productivity
If the number of areas acquired by dividing the light reception range is increased to improve processing speed, then productivity is improved, but device complexity increases
Solution Approach 1:
The light reception range is divided into multiple areas, with each area processed by a separate area calculation unit. This segmentation enables parallel processing of different regions, improving overall processing speed while keeping each individual processing circuit relatively simple.
Solution Approach 2:
Multiple area calculation units perform the same type of processing on different regions. This universality allows the system to achieve high processing throughput through parallelization without requiring each processing circuit to be highly complex or specialized.
3Productivity
If multiple processing circuits are used to measure distances in multiple areas, then productivity is improved, but reliability decreases due to lack of malfunction diagnosis
Solution Approach 1:
A malfunction detecting unit continuously monitors the operation status of area calculation units by comparing their output signals. This feedback mechanism enables real-time detection of malfunctions in any processing circuit, maintaining system reliability even as processing capability increases through parallelization.
Solution Approach 2:
The malfunction detecting unit acts as an intermediary that monitors and compares outputs from multiple area calculation units. This intermediary component provides a centralized means of detecting malfunctions without interfering with the normal processing function of the individual units.
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 solution enables efficient malfunction diagnosis and detection, reducing processing time and complexity while maintaining accurate distance measurement, thus enhancing the functional safety of in-vehicle systems.
Implementation Method 1
a plurality of light receiving elements disposed inside each of the light reception areas
Implementation Method 2
an echo detecting circuit configured to measure a distance to an object by detecting a time difference until light is reflected by the object and is received by the array unit
Data Source
AI summary
A malfunction diagnosis and malfunction detection can be efficiently performed. A light detecting device including: an array unit configured to have a plurality of light reception areas and have a plurality of light receiving elements disposed inside each of the light reception areas; a calculation unit, for each pixel including one or more light receiving elements included in each of the plurality of light reception areas, configured to generate a histogram relating to the number of times of reception of light in the light receiving element inside the pixel and a light reception timing; and a malfunction detecting unit configured to detect a malfunction of the inside of the calculation unit.