On-Board Monitoring for EU7 – Evolution vs. Revolution
- Expert Article
Christian Martin
Senior Product Manager
Michael Weissbäck
Business Field Leader
The evolutionary approach to OBM builds upon existing technologies and methodologies, leveraging established systems to meet the evolving demands of EU7 regulations. This approach emphasizes the optimization of current OBD (On-Board Diagnostics) systems, enhancing their capabilities to monitor emissions levels and detect potential issues. By reusing existing ECU (Engine Control Unit) functionalities, sensors, and empirical models, the evolutionary approach aims to streamline the transition to EU7-compliant OBM systems.
One of the primary strategies in the evolutionary approach involves refining existing sensor technologies (e.g. NOx Sensor in Diesel vehicles) to improve their accuracy and reliability in detecting emissions. Accurate modeling of emissions is important when no sensor data is available. With regard to raw emissions modeling, similar accuracy can be achieved for both engine types (gasoline and diesel engines), but there is a lack of models for tailpipe emissions stored in the control unit, especially for gasoline engines. Accurate modeling of aftertreatment systems of gasoline engines is crucial to avoid e.g. incorrect identification as a high emitting vehicle.
Additionally, the evolutionary approach focuses on optimizing software algorithms for emissions monitoring and diagnostics. This includes the development of sophisticated diagnostic routines capable of detecting deviations from expected emissions levels and identifying potential sources of malfunction or degradation. For On-Board Monitoring (OBM) purposes, continuous signal streams are needed, particularly to address cold start conditions and high-altitude operation. An evolutionary approach can act as a strategy to meet these challenges, although a revolutionary approach may also be necessary for assessing emission-influencing partial degradation.
Another key aspect of the evolutionary approach is the integration of remote monitoring and diagnostics capabilities into OBM systems. Currently, AVL is investigating, among other things, a Kalman Filter-based approach to combine emission data from virtual and real sensors, with promising results. The Kalman Filter algorithm calculates a weighting fraction based on the quality and reliability of the virtual and real sensor signals, adjusting continuously as new data becomes available. This ensures a balanced trust in both sensor inputs, leading to improved and more accurate emission results. The evaluation of the quality of the emission data is facilitated within a predefined confidence interval by a summarized estimate of the emission reliability generated by the Kalman filter. Overall, this approach enables the generation of time-resolved and distance-specific emissions, meeting OBM data provision requirements.
In contrast, the revolutionary approach seeks to push the boundaries of traditional OBD systems by incorporating virtual emission sensors and AI (Artificial Intelligence) methodologies. By leveraging advanced virtualization and software development techniques, emissions levels shall be detected in real-time and potential issues with increased accuracy and efficiency shall be identified.
One of the key innovations in the revolutionary approach is the development of virtual emission sensors that can calculate the vehicle emissions by use of simulation models. These virtual sensors utilize advanced physics-based or data-driven models to define emissions levels based on input parameters such as engine operating conditions, fuel composition, and ambient environmental factors. In addition to existing sensors, virtual emission sensors offer a cost-effective and scalable solution for OBM implementation.
Additionally, the revolutionary approach emphasizes the use of AI and machine learning algorithms for emissions monitoring and diagnostics. By analyzing large volumes of sensor data in real-time, AI-based OBM systems can detect patterns and anomalies indicative of emission violations or system malfunctions. It also enables proactive identification of potential issues before they escalate, improving the reliability and effectiveness of OBM systems in ensuring compliance with EU7 regulations. With models in place that also reflect aging effects and production scatter bands, the system is also more robust against tampering attempts.