Laser Sensor Noise Floor Stabilization via Adaptive Amplification

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Solution Overview

Problem

Current laser sensors experience inaccuracies in sensing signals due to temperature-dependent noise floors, where the fixed preset noise floor subtraction leads to large deviations in sensing results across varying temperatures.

Innovation Solution

A laser sensor with a compensation module that adjusts amplification factors based on temperature ranges, using temperature-correlated resistors in amplifying circuits to stabilize the noise floor, ensuring accurate sensing signals by minimizing noise floor variation with temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed preset noise floor is used for signal processing, then the device complexity is reduced, but the measurement precision deteriorates due to large deviations in sensing results across varying temperatures

Engineering Contradiction:
Improvesignal processing complexityVSAvoidsensing signal accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements dynamic noise floor adjustment by using temperature-dependent amplification factors in the signal processing circuit. The amplification factor changes according to temperature ranges, which dynamically adapts the noise floor compensation to current operating conditions. This resolves the contradiction by making the previously static noise floor processing dynamic and temperature-adaptive, thereby improving measurement precision without requiring complex external control systems.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the amplification factor parameter based on temperature conditions. By switching between different amplification factors corresponding to different temperature ranges, the system adjusts the effective noise floor to match actual environmental conditions. This parameter change approach improves sensing accuracy across varying temperatures while maintaining relatively simple circuit implementation.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If temperature compensation is implemented through multiple amplification circuits, then the measurement precision is improved, but the device complexity increases

Engineering Contradiction:
Improvesensing signal accuracyVSAvoidcompensation module complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the temperature compensation function into multiple amplification circuits, each handling a specific temperature range with a dedicated amplification factor. This segmentation allows precise compensation for different thermal conditions while keeping each individual circuit relatively simple. The segmentation approach resolves the contradiction by distributing the compensation task across multiple specialized circuits rather than requiring one complex universal compensator.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces temperature range detection as an intermediary mechanism that selects which amplification circuit should be active. This intermediary layer simplifies the overall system by automatically routing signals through the appropriate compensation path based on current temperature, reducing the need for complex control logic while maintaining high measurement precision across varying conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides relatively accurate sensing results by stabilizing the noise floor across temperature changes, ensuring consistent signal accuracy through adaptive amplification based on temperature ranges.

Implementation Method 1

a receiver array adapted for converting received optical signals into electrical signals

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Implementation Method 2

using temperature-correlated resistors in amplifying circuits to stabilize the noise floor

Methodology Applied
Scientific EffectTemperature correlation: Thermal Expansion

Data Source

PatentEP3599481B1Laser sensor, electronic device and computer-readable storage medium
Publication Date: 2022.04.06 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3599481B1 patent drawingFigure 1~3
  • EP3599481B1 patent drawingFigure 4~6
  • EP3599481B1 patent drawingFigure 7

AI summary

A laser sensor includes: a receiver array configured to convert received optical signals into electrical signals, wherein a noise floor of the electrical signals is positively correlated with temperature if environmental temperature is within a first preset temperature range, and negatively correlated with the temperature if the environmental temperature is within a second preset temperature range; a compensation module coupled with the receiver array and configured to receive the electrical signals, amplify the electrical signals with a first and a second amplification factors, respectively, when the environmental temperature is within the first and the second preset temperature ranges, wherein the first amplification factor is negatively correlated with the temperature and the second amplification factor is positively correlated with the temperature; and a processor coupled with the compensation module and configured to identify sensing signals based on the electrical signals amplified by the compensation module and the noise floor.