30 credits – Condition Based Maintenance for a Urea Dosing System

Scania is now undergoing a transformation from being a supplier of trucks, buses and engines to a supplier of complete and sustainable transport solutions.

Ingress:

Thesis project at Scania is an excellent way of making contacts for your future working life. Many of our current employees started their career with a thesis project.

Background:

One way of reducing NOx emissions from a diesel engine is to use SCR (Selective catalytic reduction). Heavy vehicles use a liquid called Adblue (mixture of urea and water) that is injected into the exhaust flow using a UDS (urea dosing system). The UDS on a Scania engine consists of a tank, a pump and a dosing unit as well as several interconnecting hoses. In order to maximize the customer benefit from the truck/bus/engine, it is important to minimize unplanned repair and maintenance. One way of minimizing unplanned downtime is by regular preventative service, for example changing oil at regular intervals. That leads to unnecessary service expenditure for some customers as the limits have to be set assuming worst case usage scenarios. An alternative approach is to use so called “Condition Based Maintenance”, CBM, where information from the system and prior knowledge is used to predict when certain components need to be serviced.

Scania currently has a large dataset with time resolved signals from a large fleet of field test vehicles gathered over several years. There are also databases with workshop history and operational data distributions for actual customer vehicles that can be used.

Target:

The purpose of this master thesis is to attempt to find metrics that can be used to determine a flexible service interval for the filters in the UDS. These metrics can be in the form of limits for internal control unit values, vehicle global operational data or a combination of these (or possibly others as well).

Assignment:

The candidate will work in collaboration with Scania R&D engineers in Södertälje. The work will include:

• Investigate (statistical analysis and/or hardware tests) the limits for filter blocking in the UDS and learn about the system reactions to such faults
• Study all available data sources (operational data, workshop history, failure reports, field test data etc.) and attempt to detect filters in need of change from that data
• If useable correlations can be found, develop a demonstrator (software/analysis method) that can predict suitable filter service intervals for the Scania field test fleet (and later on for customer applications)
• Make recommendations for hardware changes that would make the UDS more suitable for CBM strategies
• Review and if necessary recommend changes to the current fixed filter service intervals

Education:
– M.Sc student in Electromechanical Engineering, Engineering Physics, or equivalent

– Good knowledge in data analysis, physics, fluid dynamics and working in Matlab/Simulink and Python

– Number of students: 1
– Start date: January 2019
– Estimated time needed: 20 weeks

Contact persons and supervisors:
Kurre Källkvist, Development Engineer at Engine Control Software, , 08-553 80 379

Mats Härdelin, manager Fuel System Control, , 08-553 82 027