Lambda Probe Offset Control for Storage Catalytic Converter
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Solution Overview
Problem
The existing method for controlling the mixture composition in a drive device with an internal combustion engine and a storage catalytic converter is hindered by the sluggish reaction of the second lambda probe, leading to slow trim control and increased pollutant emissions due to the storage capacity of the catalytic converter.
Innovation Solution
Implementing a dual operating mode where the offset value is adjusted using a correction value during the regeneration period of the storage catalytic converter, allowing for rapid adaptation when the measurement signal of the second lambda probe is outside the normal operating range, and precise tuning within the normal range using a PID trim control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the second lambda probe is used for trim control to compensate for measurement errors, then the measurement precision of the first lambda probe is improved, but the response speed of the trim control deteriorates due to the storage capacity of the catalytic converter
Solution Approach 1:
The patent applies preliminary action by detecting measurement errors of the first lambda probe upstream of the catalytic converter and compensating for them before the exhaust gas reaches the second lambda probe downstream. This allows the trim control to react immediately to errors rather than waiting for the sluggish signal from after the catalytic converter, thus improving response speed while maintaining measurement precision through error compensation
2Stability of the object's composition
If the trim control is performed slowly to ensure stable control loop, then the stability of the control system is improved, but the pollutant emissions increase due to delayed correction of measurement errors
Solution Approach 1:
The patent performs preliminary error detection and compensation upstream of the catalytic converter, preventing measurement errors from causing increased pollutant emissions in the first place. This proactive approach reduces emissions while maintaining control loop stability through gradual adjustment of the trim value, avoiding the need for rapid corrections that could destabilize the system
Solution Approach 2:
The patent converts the potential harm of measurement errors (which would lead to increased emissions) into a benefit by detecting and compensating for these errors early in the process. The measurement errors are transformed from a source of pollution into an opportunity for proactive correction, reducing emissions while maintaining stable control
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 enables faster and more accurate control of the mixture composition, reducing pollutant emissions by quickly adjusting the offset value and maintaining stable operation of the internal combustion engine.
Implementation Method 1
The first oxygen sensor is disposed upstream of the storage catalytic converter, so that it can be used to measure the oxygen content in the exhaust gas at this location
Implementation Method 2
the second lambda probe is disposed downstream of the storage catalytic converter and is thus used to determine an oxygen content in the exhaust gas at this location
Implementation Method 3
The storage catalytic converter has an oxygen store for storing or temporarily storing the oxygen
Data Source
AI summary
A method for operating a drive device with an internal combustion engine and an exhaust gas tract having a storage catalytic converter for purifying exhaust gas, a first lambda probe disposed upstream of the storage catalytic converter and a second lambda probe disposed downstream of the storage catalytic converter, includes determining a lambda value for controlling a mixture composition for the internal combustion engine based on a measurement signal from the first lambda probe and an offset value. The offset value is determined with a trim control when a measurement signal of the second lambda probe is in a normal operating range of values, and is adjusted in a regeneration period, during which the storage catalytic converter regenerated, with a predetermined correction value when the measurement signal of the second lambda probe is outside the normal operating range of values. A corresponding drive device is also disclosed.