Particulate Matter Control System Failure Detection

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Solution Overview

Problem

The existing particulate matter control systems face difficulties in detecting failures, as they may not effectively aggregate particulate matter even when voltage is applied, leading to inaccurate determination of system failures due to insufficient reduction rates or erroneous strong discharge occurrences.

Innovation Solution

A particulate matter control system that includes an electrode in an exhaust pipe, a power supply, a particle number detecting unit, a calculation unit, and a determination unit, which calculates and compares the reduction rate of particulate matter before and after voltage application to determine system failures, while also using feedback control to prevent strong discharges by adjusting the applied voltage and detecting currents on the grounding side for accurate failure detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If voltage is applied to the electrode to aggregate particulate matter, then the particle number should be reduced, but the system may fail to aggregate PM effectively even when voltage is applied

Engineering Contradiction:

Improvefailure detection accuracyVSAvoidreduction rate measurement

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The system continuously monitors the particle number before and after voltage application, calculates the reduction rate, and uses this feedback to determine whether the electrode is functioning properly. When the reduction rate falls below a threshold, the system identifies this as a failure condition, enabling real-time detection and response to electrode malfunctions.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces complex electrical diagnostic systems with a simpler particle number measurement approach. Instead of monitoring electrical parameters to detect electrode failures, the system uses particle number detectors to measure the actual aggregation effect, substituting mechanical/particle-based measurement for electrical system diagnosis.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If high voltage is applied to increase aggregation efficiency, then more particulate matter can be aggregated, but strong discharge may occur causing erroneous failure determination

Engineering Contradiction:

Improveaggregation efficiencyVSAvoidstrong discharge

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system converts the potentially harmful strong discharge phenomenon into a useful diagnostic signal. By monitoring particle number changes during voltage application, the system can distinguish between intended aggregation (beneficial) and strong discharge events (harmful but detectable), using the discharge itself as an indicator to adjust voltage levels.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system dynamically adjusts the voltage parameter based on real-time particle number measurements and discharge detection. When strong discharge is detected through abnormal particle number changes or electrical parameter monitoring, the system reduces or stops voltage application, preventing erroneous failure determinations while maintaining aggregation efficiency during normal operation.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the system monitors electrical parameters to detect failures, then failure detection is possible, but the system cannot reliably distinguish between normal operation variations and actual failures

Engineering Contradiction:

Improvefailure detection capabilityVSAvoidoperational status information

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent introduces particle number as an intermediary parameter to bridge the gap between electrical operation and system performance. Instead of directly monitoring electrical parameters that are difficult to interpret, the system uses particle number measurements as a mediator to indirectly assess electrode functionality, providing clearer information about actual aggregation performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system creates a simplified copy of the aggregation process through controlled voltage application and particle number measurement. By measuring particle number before and after voltage application, the system creates a measurable signature of normal operation that can be compared against failure criteria, separating operational variations from actual failures through this simplified measurement model.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS8863496B2Particulate matter control system and its failure determination method

Publication Date: 2014.10.21 TOYOTA JIDOSHA KK

AI summary

A particulate matter control system includes: an electrode that is provided in an exhaust pipe of an internal combustion engine; a power supply that is connected to the electrode and that applies voltage; a particle number detecting unit that detects the particle number of particulate matter on a downstream side of the electrode; a calculation unit that calculates a reduction rate of the particle number at the time when voltage is applied on the basis of the particle number detected by the particle number detecting unit at the time when voltage is applied and the particle number detected by the particle number detecting unit at the time when no voltage is applied; and a determination unit that determines that there is a failure when the reduction rate of the particle number, calculated by the calculation unit, is smaller than a threshold.