Sensor Signal Compensation Filter for Response Time

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Solution Overview

Problem

Sensors often exhibit a time lag in responding to fast-changing measurements due to diffusion processes and chemical reactions, which limits their ability to provide immediate and accurate dynamic responses, especially in temperature-dependent environments.

Innovation Solution

A sensor system and method that employs a compensation filter, which uses a temperature sensor to adjust dynamic components of the sensor signal, modeled using transfer functions and implemented in a digital system, to accelerate the sensor response time by compensating for temperature-dependent dynamics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a sensor is used to measure fast varying quantities, then the sensor can detect changes in the measure, but the sensor signal exhibits time lag and cannot respond immediately to fast changes

Engineering Contradiction:
Improveresponse speedVSAvoidresponse time
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The patent applies feedback by using a compensation filter that receives the sensor signal and temperature signal, then outputs a compensated signal that corrects for the time lag. The filter uses feedback from the temperature sensor to dynamically adjust the sensor signal characteristics, effectively compensating for the sensor's inherent response delay without changing the physical sensor hardware.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the parameter of the sensor signal by applying temperature-dependent compensation factors through the compensation filter. The filter modifies the dynamic components of the sensor signal based on temperature measurements, transforming the signal characteristics to compensate for temperature-induced response time variations and improve overall response speed.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If the hardware of the sensor is modified to improve response time, then the response time decreases, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improveresponse timeVSAvoidhardware complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent substitutes the mechanical/hardware approach with a software/filter-based approach. Instead of physically modifying the sensor hardware to reduce response time, the system uses a compensation filter that processes the sensor signal in software or digital signal processing, achieving the same goal of reduced effective response time without increasing hardware complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The compensation filter acts as an intermediary between the sensor and the final measurement output. It receives the raw sensor signal and temperature data, processes them through mathematical models that account for temperature-dependent dynamics, and outputs a compensated signal that appears to respond immediately to changes, effectively hiding the sensor's inherent delays.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If temperature compensation is applied to the sensor signal, then the measurement accuracy improves, but the device complexity increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The compensation filter serves multiple functions simultaneously: it compensates for temperature-dependent response time variations, corrects for temperature-induced offset drift, and maintains measurement accuracy across different temperature conditions. By combining these compensation functions into a single filter system, the patent avoids the need for separate compensation circuits for each effect, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 compensation filter significantly reduces response time and improves the accuracy of sensor signals by accounting for temperature dependencies, enabling faster and more precise measurements in dynamic environments.

Implementation Method 1

a temperature sensor for providing a temperature signal

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

Such time lag may be owed to the appearance of diffusion processes, which may include a diffusion of the measure into the sensor - e.g. into a housing of the sensor - and, in addition, possibly a diffusion of the measure into a sensor element of the sensor

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 3

dynamic components of the sensor signal are dependent on temperature... The compensation filter is designed for adjusting the dynamic components in the sensor signal subject to the temperature signal

Methodology Applied
Scientific EffectTemperature-dependent dynamics compensation:

Data Source

PatentEP2392898B1Sensor system
Publication Date: 2017.12.13 SENSIRION AG
  • EP2392898B1 patent drawingFigure 1~2
  • EP2392898B1 patent drawingFigure 3a~3b
  • EP2392898B1 patent drawingFigure 4a~4c

AI summary

Disclosed is a method for adjusting a sensor signal and a corresponding sensor system comprising a sensor for providing a sensor signal (u(t)) representative of a measure other than temperature (T), dynamic components of the sensor signal (u(t)) being dependent on temperature (T). In addition there is provided a temperature sensor (2) for measuring the temperature (T). Dynamic components in the sensor signal (u(t)) are adjusted subject to the temperature (T) sensed, and a compensated sensor signal (y(t)) is supplied. Such sensor system helps compensating for long response times of sensors.