Exhaust Temperature Sensor Mounting Error Detection

Solution Overview

Problem

The existing systems for detecting erroneous mounting of exhaust temperature sensors in the exhaust passage of an internal combustion engine are inadequate, leading to inaccurate estimation of particulate matter deposition and temperature control during DPF regeneration, which can result in excessive particulate matter deposition, high temperatures, and potential melt damage to the DPF.

Innovation Solution

An exhaust gas purification device with a controller that detects erroneous mounting of exhaust temperature sensors by calculating the speed change deviation between inlet and outlet temperatures, using a differential approach to identify abnormal mounting positions and prevent incorrect temperature readings, thereby improving control accuracy and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple exhaust temperature sensors are mounted in the exhaust passage upstream and downstream of the DPF, then temperature sensing capability is improved, but the risk of erroneous mounting increases leading to inaccurate temperature estimation

Engineering Contradiction:

Improvetemperature sensing capabilityVSAvoidmounting position accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system performs preliminary detection of erroneous mounting by calculating the speed change deviation value before using the temperature sensors for normal operation. This preliminary check prevents incorrect temperature data from being used in subsequent control operations, thereby resolving the contradiction between having multiple sensors for precise measurement and the risk of their erroneous mounting.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the speed change deviation value and uses this feedback to detect erroneous mounting conditions. When the deviation exceeds a predetermined threshold, the system identifies an abnormal state and takes appropriate action, creating a closed-loop feedback mechanism that ensures reliable temperature sensing while maintaining the benefits of multiple sensors.

Inventive Principle:

Principle #23Feedback

2Productivity

If the DPF regeneration is performed with high temperature control, then particulate matter elimination efficiency is improved, but the risk of excessive temperature and melt damage increases

Engineering Contradiction:

Improveparticulate matter elimination efficiencyVSAvoidtemperature damage risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary detection of sensor mounting errors before initiating high-temperature regeneration operations. By checking the speed change deviation value in advance, the system prevents incorrect temperature data from triggering inappropriate regeneration control, thereby eliminating the risk of excessive temperature and melt damage while maintaining high elimination efficiency when conditions are normal.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the speed change deviation monitoring to control the regeneration process. When erroneous mounting is detected, the feedback mechanism prevents incorrect temperature control commands from being executed, thereby protecting the DPF from temperature damage while allowing efficient regeneration to proceed when sensor data is reliable.

Inventive Principle:

Principle #23Feedback

3Ease of manufacture

If the exhaust temperature sensors are mounted close to each other, then installation simplicity is improved, but the possibility of reverse mounting increases

Engineering Contradiction:

Improveinstallation simplicityVSAvoidmounting position accuracy

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The system performs preliminary detection of erroneous mounting by calculating the speed change deviation value before using the temperature sensors for normal operation. This preliminary check prevents incorrect temperature data from being used in subsequent control operations, thereby resolving the contradiction between having multiple sensors for precise measurement and the risk of their erroneous mounting.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the speed change deviation value and uses this feedback to detect erroneous mounting conditions. When the deviation exceeds a predetermined threshold, the system identifies an abnormal state and takes appropriate action, creating a closed-loop feedback mechanism that ensures reliable temperature sensing while maintaining the benefits of multiple sensors.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS7797930B2Exhaust gas purification device of internal combustion engine

Publication Date: 2010.09.21 DENSO CORP

AI summary

An ECU performs exhaust temperature control based on output values of multiple exhaust temperature sensors provided upstream and downstream of a particulate filter provided in an exhaust passage of an engine. The ECU calculates a change speed deviation value by subtracting change speed of outlet side exhaust temperature, which is sensed by one of the exhaust temperature sensors, from change speed of inlet side exhaust temperature, which is sensed by the other one of the exhaust temperature sensors, in an operation state in which temperature of exhaust gas flowing through the particulate filter changes rapidly. The ECU determines that the exhaust temperature sensors are mounted erroneously if the change speed deviation value deviates from a predetermined normal range.