Particle Sensor Regeneration Control for Electrode Protection

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Solution Overview

Problem

High-temperature regeneration of particle sensors, particularly those with platinum electrodes, can lead to long-term damage due to exposure, as they are required to reach high temperatures for soot burn-off, affecting their service life and accuracy in subsequent measurements.

Innovation Solution

A method involving a first regeneration at a lower temperature, followed by diagnostic measurements to determine if a second, higher regeneration is necessary, allowing for conditional and controlled heating to ensure complete particle burn-off while minimizing electrode damage, using a controller to manage regeneration temperatures and diagnostic processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sensor element is heated to high temperature for regeneration, then soot burn-off is achieved, but electrode damage occurs

Engineering Contradiction:
Improvesoot burn-off effectivenessVSAvoidelectrode integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the regeneration temperature based on diagnostic measurements. The controller modifies the temperature parameter from a fixed high value to a variable value that adapts to the actual soot load condition, thereby achieving effective burn-off while minimizing electrode exposure to damaging temperatures

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements local quality by applying different temperature levels to different operational phases: a lower temperature during the first regeneration phase and a higher temperature during the second regeneration phase. This spatial-temporal differentiation of temperature quality allows effective soot removal while protecting the electrode from continuous high-temperature exposure

Inventive Principle:
Principle #3Local quality

2Measurement precision

If frequent high-temperature regeneration is performed, then measurement accuracy is maintained, but service life is reduced

Engineering Contradiction:
Improveparticle detection accuracyVSAvoidsensor service life
Core Design Contradiction:
Measurement precisionVSDuration of action of stationary object

Solution Approach 1:

The patent applies dynamics by transitioning from a static regeneration strategy (fixed high temperature) to a dynamic strategy where regeneration temperature and frequency are adjusted based on real-time diagnostic measurements. The controller continuously monitors electrode state and adapts the regeneration process, making the system responsive to actual conditions rather than following a predetermined schedule

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback through diagnostic measurements that monitor the electrode state before and after regeneration. The controller uses this feedback information to determine whether the first regeneration was sufficient and whether a second high-temperature regeneration is necessary, thereby avoiding unnecessary high-temperature cycles that would reduce service life

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 extends the service life of particle sensors by reducing the risk of electrode damage and ensuring accurate measurements, enabling operation beyond 250,000 km with reduced risk of metal evaporation and maintaining sensor effectiveness.

Implementation Method 1

heating the sensor element, in particular the measuring electrode, to the comparatively high temperature required for soot burn-off

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

the at least one measuring electrode, for example the interdigital electrode (IDE), is brought into a defined, preferably soot-free, state that can serve as the starting point for a particle measurement

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 3

The particles accumulating under the action of a voltage, in particular the soot particles, form electrically conductive bridges in a collecting phase of the sensor element between the electrodes designed, for example, as comb-like interdigitated interdigital electrodes and thereby short-circuit them

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3545283B1Method for operating a sensor element for detecting particles of a measurement gas in a measurement gas chamber
Publication Date: 2021.06.23 ROBERT BOSCH GMBH
  • EP3545283B1 patent drawingFigure 1

AI summary

The invention relates to a method for operating a sensor element for detecting particles of a measurement gas in a measurement gas chamber. The sensor element comprises a mount and at least one measuring electrode which is connected to the mount and can be exposed to the measurement gas. The method comprises the following steps: a) carrying out a first regeneration of the sensor element at a first regeneration temperature; b) carrying out a first diagnostic measurement at the measuring electrode; and c) carrying out at least one of the following steps depending on a result of the first diagnostic measurement: c1) issuing an error message; c2) carrying out a measurement phase for detecting the particles of the measurement gas; or c3) carrying out a second regeneration of the sensor element at a second regeneration temperature.