Powertrain Shift Control for Three-Way Catalyst Temperature Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing powertrain control systems face challenges in maintaining a stoichiometric air-fuel ratio over the entire engine operation range while preventing thermal deterioration of the three-way catalyst and ensuring adequate engine output, leading to reduced driving performance.
Innovation Solution
A powertrain control device that includes an engine control module for intake air charge amount limit control and a transmission control module for forced upshift control, which adjusts the intake air charge amount and automatically shifts gears to maintain the stoichiometric air-fuel ratio and prevent catalyst overheating, while ensuring sufficient engine output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If intake air charge amount is limited to prevent three-way catalyst overheating, then catalyst temperature is controlled within allowable range, but engine output becomes insufficient and vehicle speed does not increase
Solution Approach 1:
The invention dynamically adjusts the throttle opening degree based on real-time detection of three-way catalyst temperature and engine operating conditions. The ECU modifies the throttle opening degree from the initially calculated value when catalyst temperature approaches or exceeds the allowable temperature, thereby dynamically balancing catalyst temperature control with engine output requirements.
Solution Approach 2:
The invention changes the throttle opening degree parameter based on detected catalyst temperature and engine operating conditions (intake air temperature, engine revolution speed, load). By adjusting this parameter, the system optimizes the balance between limiting intake air charge to control catalyst temperature and maintaining sufficient engine output for desired vehicle speed.
2Reliability
If entire-range stoichiometric air-fuel ratio operation is performed to achieve high emission purification rate, then exhaust emissions are effectively removed, but amount of heat in exhaust gas increases causing three-way catalyst temperature to exceed allowable temperature
Solution Approach 1:
The invention uses feedback from the three-way catalyst temperature detector to continuously monitor catalyst temperature and adjust the throttle opening degree accordingly. The ECU detects the catalyst temperature and modifies the intake air charge amount based on this feedback, ensuring the catalyst temperature remains within the allowable range while maintaining stoichiometric air-fuel ratio operation for high purification rates.
Solution Approach 2:
The invention changes the throttle opening degree parameter based on detected catalyst temperature and engine operating conditions. By adjusting this parameter, the system optimizes the balance between maintaining stoichiometric air-fuel ratio for high emission purification and limiting intake air charge to control catalyst temperature within allowable ranges.
3Reliability
If throttle opening degree is regulated to prevent three-way catalyst temperature from exceeding allowable temperature, then catalyst thermal deterioration is prevented, but intake air charge amount becomes lower than required amount causing insufficient engine output
Solution Approach 1:
The invention dynamically adjusts the throttle opening degree based on real-time detection of three-way catalyst temperature and engine operating conditions. The ECU modifies the throttle opening degree from the initially calculated value when catalyst temperature approaches or exceeds the allowable temperature, thereby dynamically balancing catalyst temperature control with engine output requirements.
Solution Approach 2:
The invention changes the throttle opening degree parameter based on detected catalyst temperature and engine operating conditions (intake air temperature, engine revolution speed, load). By adjusting this parameter, the system optimizes the balance between limiting intake air charge to control catalyst temperature and maintaining sufficient engine output for desired vehicle speed.
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 system achieves advanced emission performance by maintaining the three-way catalyst at an appropriate temperature and preventing a reduction in vehicle speed, thus enhancing driving performance.
Implementation Method 1
an exhaust gas purification apparatus that purifies, using a three-way catalyst, exhaust gas exhausted from the engine
Implementation Method 2
it is possible to reduce the amount of heat in the exhaust gas by making use of the heat of vaporization of fuel
Data Source
AI summary
Provided is a powertrain control device for a vehicle including an exhaust gas purification apparatus and an automatic transmission, the vehicle traveling by controlling an engine and the automatic transmission. The powertrain control device includes an engine control module (ECM) and a transmission control module (TCM). The ECM performs entire-range stoichiometric air-fuel ratio operation control, and also performs intake air charge amount limit control when an intake air charge amount reaches an upper limit value that is set to prevent a temperature of a three-way catalyst from exceeding an allowable temperature. The TCM performs automatic shift control, and performs forced upshift control of forcibly shifting up the automatic transmission when an engine revolution speed reaches a revolution limit. When the ECM limits the intake air charge amount, the TCM performs revolution limit change control of lowering the revolution limit.