Lidar Sensor Maximum Range Determination via Test Mode

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Solution Overview

Problem

Existing LIDAR sensors face challenges in determining their maximum range, especially in adverse visibility conditions, due to the complexity and cost of current methods, which can lead to undetected objects and safety issues.

Innovation Solution

The method involves periodically interrupting normal operation with a test operation that reduces transmission power and reception sensitivity, allowing for the determination of a lower limit for the maximum range by identifying objects no longer detectable during the test, using empirically determined data to estimate the range in real-time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex analog-to-digital conversion with high temporal resolution is used to determine maximum range, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvemaximum range determination accuracyVSAvoidanalog-to-digital converter complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential information needed for maximum range determination from the backscattered signal, rather than performing complete high-resolution analog-to-digital conversion. By identifying specific signal characteristics (threshold crossings, pulse shapes) that indicate maximum range, the system achieves accurate measurement without the complexity of expensive ADCs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses simple, cost-effective evaluation electronics that perform basic signal thresholding and timing measurements instead of expensive high-resolution analog-to-digital converters. This approach sacrifices some measurement capability but provides sufficient accuracy for maximum range determination at a fraction of the cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Device complexity

If threshold-based evaluation is used to simplify signal processing, then device complexity is reduced, but measurement precision deteriorates due to inability to analyze signal form

Engineering Contradiction:
Improvesignal evaluation simplicityVSAvoidmaximum range determination accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary signal processing by applying thresholds to the backscattered signal before full evaluation. This preliminary action identifies candidate regions and signal characteristics that guide subsequent more precise measurements, enabling accurate maximum range determination with simpler overall system architecture.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses dynamic thresholding and adaptive evaluation methods where the threshold levels and evaluation criteria are adjusted based on signal characteristics and operating conditions. This dynamic approach maintains measurement precision across varying signal strengths while keeping the evaluation electronics relatively simple.

Inventive Principle:
Principle #15Dynamics

3Productivity

If normal operation continues without interruption to maintain productivity, then productivity is improved, but reliability deteriorates due to inability to detect reduced maximum range in adverse conditions

Engineering Contradiction:
Improvecontinuous operation efficiencyVSAvoiddetection capability in adverse conditions
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements periodic interruption of normal LIDAR operation to perform test operations that determine the current maximum range. These periodic tests allow the system to detect changes in environmental conditions (fog, rain, darkness) that affect detection capability, maintaining reliability while minimizing interruption to productivity through scheduled rather than continuous testing.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent uses feedback from the periodic test operations to adjust the operational parameters and safety margins during normal operation. When test operations indicate reduced maximum range due to adverse conditions, the system can alert the driver or adjust detection thresholds, maintaining safety while allowing continuous productive operation.

Inventive Principle:
Principle #23Feedback

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 provides a simple, reliable, and cost-effective means to determine the maximum range of LIDAR sensors in real-time, enabling proactive safety measures and reducing production and power consumption costs.

Implementation Method 1

The sensor carries out a transit time measurement of the emitted infrared laser beams. The time that the laser light needs from the sensor to the illuminated object and back again is measured.

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Implementation Method 2

receiving a backscattered portion of the LIDAR signal

Methodology Applied
Scientific EffectLight backscattering: Scattering

Data Source

PatentEP3665505B1Determining the maximum range of a lidar sensor
Publication Date: 2023.07.26 VALEO SCHALTER & SENSOREN GMBH
  • EP3665505B1 patent drawingFigure 1~3

AI summary

The invention relates to determining the maximum range of a LIDAR sensor (2). For this purpose, according to the invention, an operating method for a LIDAR sensor (2) is provided, with the following steps: transmitting a LIDAR signal (4) at a predetermined normal power and receiving a backscattered portion of the LIDAR signal (4) at a predetermined normal sensitivity in order to determine the distance of objects (11, 12, 13, 14), which are present in the environment scanned by the LIDAR sensor (2), in a normal mode, characterized by repeated interruption of the normal mode by a test mode, wherein the test mode comprises the following steps: transmitting a LIDAR signal (4) at a test power which is reduced by a predetermined extent in relation to the predetermined normal power and/or receiving the backscattered portion of the LIDAR signal (4) at a test sensitivity which is reduced by a predetermined extent in relation to the predetermined normal sensitivity, and determining a value for the maximum range of the LIDAR sensor (2), which range exists in the normal mode of the LIDAR sensor (2), on the basis of the distance, determined in the normal mode, of objects (13, 14) of this type that are no longer detected in the test mode. Such an option is therefore provided for determining the maximum range of a LIDAR sensor (2) and can be used simply, reliably and cost-effectively.