Lidar Reference Receiver Channel Gain Adjustment

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Solution Overview

Problem

Light detection and ranging (Lidar) systems in automotive applications face challenges due to mismatch between optical receiver channels, leading to detection errors and reduced availability.

Innovation Solution

The system incorporates a reference receiver channel and comparators to adjust the gain of amplifiers in separate receiver channels, ensuring matched output across channels by comparing outputs to the reference channel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If separate optical receiver channels are used for each optical sensor, then the system can process multiple sensor signals simultaneously, but mismatch between channels leads to detection errors and reduced reliability

Engineering Contradiction:
Improveparallel signal processing capabilityVSAvoiddetection accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the output of each receiver channel is fed back to its corresponding amplifier. The amplifier adjusts its gain based on the feedback signal to equalize the output levels across all channels. This closed-loop feedback system continuously compensates for mismatches in optical sensor responsivity and amplifier characteristics, ensuring reliable detection accuracy while maintaining parallel processing capability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically changes the gain parameter of each amplifier based on the actual performance characteristics of its corresponding optical sensor. By measuring the output level of each channel and adjusting the amplifier gain accordingly, the system adapts to variations in sensor responsivity and maintains consistent detection accuracy across all channels

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If amplifier gain is trimmed at low frequency, then matching between receiver channels is improved, but aging and stress over lifetime cause further mismatch

Engineering Contradiction:
Improvechannel matching accuracyVSAvoidsystem lifetime performance stability
Core Design Contradiction:
Manufacturing precisionVSDuration of action of stationary object

Solution Approach 1:

The patent implements continuous gain adjustment throughout the system's operational lifetime, rather than a one-time trim during manufacturing. The feedback mechanism operates continuously, constantly monitoring and adjusting amplifier gains to compensate for aging effects, thermal drift, and stress-induced changes in optical sensors and amplifiers, thereby maintaining channel matching accuracy throughout the entire system lifetime

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system performs self-adjustment of amplifier gains without requiring external intervention or recalibration. The feedback loop automatically detects mismatches and corrects them by adjusting the amplifier parameters, enabling the system to self-compensate for component aging and environmental changes throughout its operational life

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If different optical sensors are used by different customers, then system versatility is improved, but mismatch between channels increases

Engineering Contradiction:
Improveoptical sensor selection flexibilityVSAvoidreceiver channel matching
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies local quality adjustment by individually tailoring the gain of each amplifier to match its corresponding optical sensor's characteristics. Instead of requiring all sensors to be uniformly matched, the system locally adapts each amplifier's gain parameter to compensate for the specific sensor's responsivity variations, enabling the use of different sensor types while maintaining overall channel matching

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes the gain parameter of each amplifier based on the specific optical sensor connected to that channel. By measuring the actual output level of each sensor-amplifier combination and adjusting the amplifier gain accordingly, the system accommodates different optical sensors from various manufacturers while maintaining consistent detection accuracy across all channels

Inventive Principle:
Principle #35Parameter changes

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 online detection and correction of mismatches, enhancing the predictability, accuracy, and resolution of Lidar systems while allowing flexibility in choosing optical sensors.

Implementation Method 1

multiple receiving optical sensors (4) for receiving a light signal from the surroundings of the light detection and ranging system

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

each separate receiver channel comprising an amplifier (9) with adjustable gain for amplifying the signal of the corresponding receiving optical sensor

Methodology Applied
Scientific EffectElectrical amplification:

Data Source

PatentEP4160264B1Lidar system with reference receiver channel, suitable optical receiver and corresponding lidar operating method
Publication Date: 2025.04.16 RENESAS ELECTRONICS AMERICA INC
  • EP4160264B1 patent drawingFigure 1
  • EP4160264B1 patent drawingFigure 2~3

AI summary

The invention relates to a light detection and ranging system (1) additionally comprising: a reference receiver channel (12) and at least one comparator (13) for comparing the output of the reference receiver channel (12) and the output of each of the separate receiver channels (8) to a second emitted light signal (11), the reference receiver channel (12) comprising a reference optical sensor (14) and a reference amplifier (15), wherein the at least one comparator (13) can adjust the gain of the amplifiers (9) of each separate receiver channels (8) based on the result of the comparison of the output of the reference receiver channel (12) and the output of the corresponding separate receiver channel (8). The invention further relates to an optical receiver system (7) and a method for operating a light detection and ranging system (1) .