Exhaust Gas Sensor Heating Control for Hybrid Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In hybrid vehicles with exhaust gas sensors and separate heating devices, precise control of heating is challenging due to varying environmental conditions, leading to potential heat shock and reduced sensor durability, as well as delays in air-fuel ratio feedback control.
Innovation Solution
A vehicle control apparatus and method that includes an environmental condition sensing mechanism to estimate condensation occurrence temperature based on atmospheric conditions and engine parameters, allowing for precise heating control of the exhaust gas sensor by adjusting the heating device's performance accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate heating device is used to heat the exhaust gas sensor to activation temperature, then the sensor can output accurate sensing signals, but condensation may occur causing heat shock and sensor failure
Solution Approach 1:
The system performs preliminary heating of the exhaust gas sensor before engine restart after idle stop, ensuring the sensor reaches activation temperature before cold exhaust gas containing condensation enters the sensor. This preliminary action prevents condensation-related heat shock while maintaining sensing accuracy.
Solution Approach 2:
The control system uses feedback from engine operating conditions (idle stop detection, exhaust temperature estimation) to dynamically control the heating device. When condensation is likely to occur, the system adjusts heating timing and intensity to prevent heat shock while still achieving sensor activation.
2Device complexity
If the condensation occurrence temperature is set to a substantially constant value, then the control logic is simplified, but heating may be stopped incorrectly or continued when condensation occurs
Solution Approach 1:
The system changes the approach from using a constant temperature threshold to using dynamic parameters including engine operating conditions, exhaust gas temperature estimation, and environmental conditions. This allows accurate determination of condensation occurrence without oversimplification.
Solution Approach 2:
The heating control system transitions from static constant-temperature control to dynamic control that adapts to changing engine conditions, exhaust temperature, and environmental factors. This dynamic approach accurately tracks condensation conditions while maintaining reliable sensor heating.
3Loss of energy
If the engine is automatically stopped in hybrid vehicles, then fuel efficiency is improved, but precise heating control of the exhaust gas sensor becomes difficult due to varying environmental conditions
Solution Approach 1:
Before engine restart after idle stop, the system performs preliminary heating of the exhaust gas sensor based on predicted condensation conditions. This ensures the sensor is ready for accurate sensing immediately upon restart, maintaining fuel efficiency while achieving reliable sensor operation.
Solution Approach 2:
The system adjusts heating parameters based on environmental conditions (ambient temperature, humidity) and engine state (idle stop duration, exhaust temperature). This dynamic parameter adjustment maintains precise heating control despite varying conditions in hybrid vehicle operation.
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A vehicle control apparatus and methodology relate to an exhaust gas sensor and sensor heater associated with an exhaust passage of a vehicle engine. The exhaust gas sensor is selectively heated to an applicable activation temperature by the heater so that the sensor may output a normal and accurate sensing signal. The heating must take place, however, without causing damage to the sensor such as that resulting from condensation that may occur within the exhaust passage as a result of engine operation and environmental conditions.