Adaptive Threshold for Electrically Heated Catalyst Abnormality Detection
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Solution Overview
Problem
In hybrid vehicles, the detection of abnormalities in electrically heated catalysts is challenging due to varying battery consumption rates, leading to inconsistent exhaust emission levels during engine startup, especially when switching between EV and HV modes, and existing methods fail to accurately identify abnormalities that increase exhaust emissions.
Innovation Solution
An abnormality detection apparatus that adjusts thresholds based on battery charge level decrease rates to compare actual electrical energy supplied to the electrically heated catalyst with a specific threshold, enabling accurate detection of abnormalities that could lead to increased exhaust emissions by calculating and comparing electrical energy parameters over a specific period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the supply of electrical power to the electrically heated catalyst is stopped halfway due to high battery consumption rate, then the battery charge level is maintained, but the detection accuracy of catalyst abnormalities decreases and exhaust emissions increase
Solution Approach 1:
The patent applies dynamics by making the threshold value adaptive rather than fixed. The threshold for abnormality detection is dynamically adjusted based on the actual electrical energy supplied to the catalyst, which varies when power supply is interrupted. This allows the system to maintain accurate detection capabilities despite changing operating conditions and partial power supply scenarios.
Solution Approach 2:
The patent changes the parameter being measured from fixed electrical energy thresholds to rate-based thresholds. By calculating the rate of electrical energy supply (power divided by time) and comparing it against dynamically determined thresholds, the system can accurately detect abnormalities even when total energy supply is reduced due to interruptions. This parameter transformation enables reliable detection under variable power supply conditions.
2Loss of energy
If the supply of electrical power to the electrically heated catalyst is stopped halfway, then battery consumption is controlled, but the heating temperature of the catalyst is insufficient and exhaust emissions increase
Solution Approach 1:
The patent implements feedback by continuously monitoring the actual electrical energy supplied to the catalyst and using this information to adjust the abnormality detection threshold. The system calculates the rate of energy supply and compares it against dynamically updated thresholds, creating a closed-loop control mechanism that adapts to partial power supply scenarios and maintains effective catalyst operation.
Solution Approach 2:
The patent applies preliminary action by pre-calculating and storing threshold values that correspond to different rates of electrical energy supply. When power supply conditions change, the system can immediately switch to the appropriate threshold without delay, enabling rapid adaptation to varying power availability and maintaining emission control effectiveness.
3Device complexity
If a fixed threshold is used for abnormality detection, then the detection method is simple, but it cannot accurately detect abnormalities when power supply duration varies
Solution Approach 1:
The patent transforms the detection system from static to dynamic by making the threshold adaptive. Instead of using a fixed threshold value, the system calculates thresholds based on the actual rate of electrical energy supply, which varies with power supply duration and intensity. This dynamic approach maintains detection accuracy across different operating conditions without requiring complex additional hardware.
Solution Approach 2:
The patent changes the detection parameter from fixed electrical energy thresholds to rate-based thresholds. By measuring power supply rate (energy per unit time) and comparing it against dynamically determined thresholds, the system achieves accurate abnormality detection regardless of whether power supply is complete or interrupted. This parameter transformation simplifies the detection logic while improving reliability.
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 apparatus effectively detects abnormalities in electrically heated catalysts, ensuring accurate identification of issues that increase exhaust emissions, even when power supply is stopped halfway, thereby enhancing cleaning performance and reducing emissions during engine startup.
Implementation Method 1
a heating element that generates heat when supplied with electrical power, the electrical resistance of the heating element being larger when its temperature is low than when it is high
Data Source
AI summary
The electrically heated catalyst to which the present disclosure is applied is provided in a hybrid vehicle capable of switching its running mode between EV mode and HC mode and supplied with electrical energy before the internal combustion engine is started. An abnormality detection apparatus calculates an electrical energy parameter relating to the integrated value of electrical power actually supplied to the electrically heated catalyst (actually supplied electrical power) over a specific period of time from the time when supply of electrical power to the electrically heated catalyst is started and detects an abnormality of the electrically heated catalyst by comparing the electrical energy parameter with a threshold. The threshold is set according to the rate of decrease of the charge level of a battery (charge level decrease rate) during a period in which electrical power is supplied to the electrically heated catalyst.