Abstract
KEYWORDS – Defeat Device, Real Driving Emissions, RDE, Fuel Consumption, CO2 Emissions
ABSTRACT
Research question
The recent Volkswagen emissions scandal has sparked a lot of interest from various parties related to defeat devices, in particular how they can be identified and more importantly how they can be avoided during the product development process, for example by using a structured process, selecting appropriate technologies, providing appropriate training about defeat devices and by implementing suitable business structures. It appears that no relevant publication or training is publically accessible, therefore this paper will provide an overview about the topic and provide answers to some of these questions.
Methodology
The report starts with a literature study that gives an overview about previous cases where defeat devices have been identified together with guidelines and best practices that have been published by regulators and industry. An example of potential defeat device has been identified through analysis of test reports that were published by government agencies in different countries. A modification of this device is proposed to bring it in line with regulatory requirements and to reduce NOx emissions and fuel consumption during real world driving and certification tests.
Results
The proposed solutions include new approaches to vehicle hardware and software. An example of the hardware solution is a new configuration of a vehicle’s cooling system. Various reports have shown that RDE emissions, particularly NOx, increase if a drive cycle is started with an engine that has already been warmed up instead of a cold start. Therefore it is essential to provide adequate cooling to all engine components that are part of the emission control system and as such are influencing the formation of emissions.
Limitations
Up until now the study is only based on literature research and subsequent conceptual solutions. Although the report provides a comprehensive overview and as such fills a gap in this very sensitive area, in a next step the proposed test procedures, effectiveness definitions and organizational structures should be discussed with legislators and government agencies in different parts of the world. The technical solutions to minimize RDE emissions have not been proven yet in physical demonstrator vehicles. This will be the subject of subsequent studies and reports so that a timely introduction into mass production can be ensured. Novelty Some of technical solutions have recently been included in a new patent application. Conclusions An overview about defeat devices is presented together with proposals to avoid them and to reduce emissions and fuel consumption. This should help vehicle manufacturers early in the product development process to take all necessary actions to avoid the risk of producing products with technologies that could be interpreted as defeat device.