Motor Vehicle Drive Device Lambda Setpoints for Catalyst Efficiency
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Solution Overview
Problem
Existing methods for adjusting the composition of the fuel-fresh gas mixture in motor vehicle drive devices are not precise, leading to inefficiencies in pollutant conversion by the exhaust gas aftertreatment system.
Innovation Solution
Selecting target values for combustion air ratios based on predefined stored values and operating states, independent of real-time combustion air ratios, to adjust the fuel-fresh gas mixture composition, using lambda probes upstream and downstream of the exhaust gas aftertreatment device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If real-time feedback control based on lambda probe signals is used to adjust fuel injection, then the system can maintain stable combustion air ratio, but the precision is insufficient during transient operating states such as temperature changes and operational state transitions
Solution Approach 1:
The control method determines a preliminary target combustion air ratio based on the current operating state (temperature, load, etc.) before adjusting fuel injection. This preliminary determination accounts for transient conditions and prepares the appropriate target value in advance, improving control precision during transitions without requiring complex real-time adjustments
Solution Approach 2:
The system dynamically adapts the target combustion air ratio based on changing operating states. Different operating states (cold start, warm-up, steady-state, transient) have different predetermined target values, allowing the control system to be versatile across various conditions while maintaining precision in each state
2Productivity
If the exhaust gas aftertreatment system operates without precise mixture control, then the system structure remains simple, but the conversion efficiency of pollutants decreases
Solution Approach 1:
The control method adjusts the target combustion air ratio based on operating state parameters (temperature, load, etc.) to optimize pollutant conversion efficiency. By changing the target ratio parameter according to temperature and operational state, the system achieves high conversion efficiency without requiring complex additional hardware
Solution Approach 2:
The system uses feedback from lambda probes (upstream and downstream of the aftertreatment device) to monitor combustion air ratio and adjusts fuel injection accordingly. This feedback mechanism enables precise control for optimal pollutant conversion while maintaining a relatively simple control structure
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
This approach allows for precise adjustment of the fuel-fresh gas mixture, enhancing the conversion efficiency of the exhaust gas aftertreatment system and reducing emissions, particularly during temperature and operational state changes.
Implementation Method 1
a first lambda probe arranged upstream of the exhaust gas aftertreatment device for determining a first combustion air ratio in the exhaust gas, and a second lambda probe arranged downstream of the exhaust gas aftertreatment device for determining a second combustion ratio in the exhaust gas
Implementation Method 2
an exhaust gas aftertreatment device configured as a vehicle catalyst for aftertreating the exhaust gas
Data Source
Figure 1
AI summary
The invention relates to a method for operating a drive device (1) for a motor vehicle, which drive device has a drive unit (2) generating exhaust gas, an exhaust gas aftertreatment device (4) designed as a vehicle catalyst for aftertreating the exhaust gas, a first lambda probe (6) arranged upstream of the exhaust gas aftertreatment device (4) for determining a first combustion air ratio in the exhaust gas, and a second lambda probe (7) arranged downstream of the exhaust gas aftertreatment device (4) for determining a second combustion air ratio in the exhaust gas, wherein a composition of a fuel-fresh gas mixture used to operate the drive unit (2) is adjusted based on the first combustion air ratio and/or the second combustion ratio.It is provided that a target value to which the first combustion air ratio or the second combustion air ratio is set is selected from several stored preset target values depending on an operating state of the drive unit (2). The invention further relates to a drive device (1) for a motor vehicle and a computer program product.